Praise be to Allah.

Firstly: 

These myths – and many others – come under the heading of superstition that is forbidden in Islam. There is no limit to such myths among the people. Some regard seeing certain things as a bad omen – such as seeing an owl or a black cat; some regard hearing certain things as a bad omen – such as hearing the sound of an owl or a crow. They even regard verses in the Book of Allaah as omens, if it is seen in the Mus-haf or heard from one who is reading! – such as a verse which speaks of warning or punishment. Some of them regard numbers as unlucky, such as 13; or they regard certain times as unlucky times, such as Wednesdays, or the month of Shawwaal for those who want to get married. Some regard certain places as unlucky, such as a place in which a crime occurred, or they regard certain types of people as a bad omen, such as the lame or the blind, or the poor or needy. 

It was narrated from Anas ibn Maalik (may Allaah be pleased with him) that the Prophet SAWS (peace and blessings of Allaah be upon him) said: “There is no ‘adwa (transmission of infectious disease without the permission of Allaah) and no tiyarah (superstitious belief in bird omens), but I like optimism.” They said, “What is optimism?” He said, “A good word.”  Narrated  by al-Bukhaari (5776) and Muslim (2224). 

It was narrated that ‘Abd-Allaah ibn Mas’ood said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Tiyarah (superstitious belief in omens) is shirk.” Narrated by al-Tirmidhi (1614), Abu Dawood (3910), Ibn Majaah (3538); classed as saheeh by al-Albaani in Saheeh Abi Dawood. 

Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) said: 

The word tiyarah is derived from the word tatayyur, which refers to superstition about something that is seen or heard; or it was said that it refers to superstition about anything ,whether it is something that is seen or heard, or a time or place. This is more comprehensive as it includes things that are not seen or heard, such as superstition about certain times. 

The basic meaning of tatayyur is pessimism but reference is made to birds (tayr) because most of the superstitions held by the Arabs have to do with birds, so it was connected to them. But the general definition is superstition based on something that is seen, heard or known. 

The Arabs used to regard certain birds, times and persons as unlucky, and this is shirk as the Prophet (peace and blessings of Allaah be upon him) said. 

If a person opens the door to superstition, the world will become a hard place for him and he will imagine that everything is a bad omen. There are even some people who, if they get up in the morning and go out and meet a man who only has one eye, they will regard it as a bad omen and say: Today is a bad day, so such a person will close his shop and not sell or buy anything – Allaah forbid. Some of them regarded Wednesday as unlucky and said that it was a day of bad omens and bad luck, and some of them regarded the month of Shawwaal as unlucky, especially for weddings. The case of ‘Aa’ishah proves that this superstition is wrong, because the Prophet (peace and blessings of Allaah be upon him) married her in Shawwaal and consummated the marriage with her in Shawwaal, so she used to say: “And who among you was more beloved to him than me?” Narrated by Muslim. The answer is: No one. 

What matters is that no one should pay any attention to superstition, because it will spoil his life. What we should do is follow the example of the Prophet (peace and blessings of Allaah be upon him) who liked optimism, as was narrated by al-Bukhaari and Muslim. We should be optimistic, not pessimistic, like some people who try something time after time, then they become pessimistic and think that they will never succeed in it, so they give it up. This is wrong, because if you think that something is good, you should not give it up at the first attempt; try again and again until Allaah makes it easy for you. 

Al-Qawl al-Mufeed Sharh Kitaab al-Tawheed (2/39-41); Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen (9/515, 516). 

Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said:  

Al-Bayhaqi quoted from al-Haleemi in al-Shu’ab what may be summed up as follows: 

During the Jaahiliyyah, tatayyur (seeking bird omens) was when the Arabs would disturb birds when wanting to go out on a necessary journey. … They also used to regard the voice of a crow and the passing of gazelles as bad omens, but they called all them tatayyur because the original omen had to do with birds (tayr).  

He said: There were also superstitions among the non-Arabs. If a person saw a child going to the teacher, he would regard it as a bad omen, and if he saw the child returning he would regard it as a good omen. If they saw a camel carrying a heavy load they would regard it was a bad omen and if they saw it carrying no load they would regard it as a good omen, and so on. 

Islam abolished all of that. 

Fath al-Baari (10/215). 

Superstition is only mentioned in the Qur'aan as something followed by the enemies of the Messengers, which indicates that the one who follows it and believes in it is as ignorant as those people, to the extent that he believes in these notions. 

Ibn al-Qayyim (may Allaah have mercy on him) said: 

Allaah does not mention superstition except on the part of the enemies of the Messengers, as they said to their Messengers (interpretation of the meaning): 

“ ‘For us, we see an evil omen from you; if you cease not, we will surely stone you, and a painful torment will touch you from us.’

19. They (Messengers) said: ‘Your evil omens be with you! (Do you call it ‘evil omen’) because you are admonished? Nay, but you are a people Musrifoon (transgressing all bounds by committing all kinds of great sins, and by disobeying Allaah)’”

[Ya-Seen 36:18, 19]

And Allaah tells us about the people of Pharaoh (interpretation of the meaning): 

“But whenever good came to them, they said: ‘Ours is this.’ And if evil afflicted them, they ascribed it to evil omens connected with Moosa (Moses) and those with him. Be informed! Verily, their evil omens are with Allaah”

[al-A’raaf 7:131]

Miftaah Daar al-Sa’aadah (3/231, 232) 

Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said of the people of the Jaahiliyyah: 

Most of them believed in bird omens and relied in that, and they usually came true for them, because the shaytaan was making it appear attractive to them, and some traces of that are still present among many Muslims. 

Fath al-Baari (10/213). 

The scholars also drew attention to some myths that are widespread among the people, which they take as a bad omen that may lead to a break in family ties, corruption or divorce. 

The scholars of the Standing Committee were asked: 

When my marriage contract was being done, I cracked my knuckles and I was not aware the interlacing my fingers and cracking my knuckles could lead to problems in the marriage. After I found out, I felt too shy to ask, and I have three children and have been married for seven years. What should I do? Should I do a new marriage contract or what should I do? 

They replied: 

If the situation is as you describe, what you mention about interlacing your fingers and the cracking of your knuckles whilst your marriage contract was being done has no effect on the validity of the marriage, rather your marriage is valid and there is no need to do the contract again. Give up superstitious beliefs in the things you mentioned and in other things because it is contrary to Islam. 

Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan. 

Fataawa al-Lajnah al-Daa’imah (18/114). 

Everything that is mentioned in the question comes under the same heading and these are things that the shaytaan has instilled in the minds of a lot of people and made them regard as bad omens things that have no effect on their lives in reality, because the Muslims swim in water and sprinkle one another with water, and children play in swimming pools, and it is not known to have any negative effect on them.  The same may be said about the myths concerning opening and closing scissors, stepping over a child, cutting one's nails at night, sweeping the house at night, refusing to do laundry on Mondays, and other limitless myths and illusions that make them fear things which need not be feared and keep them from striving and being optimistic, and keep them from putting their trust fully in their Lord. 

Ibn al-Qayyim (may Allaah have mercy on him) said:  

Tatayyur refers to superstitions about something that is seen or heard; if a person follows it  and he changes his mind about travelling or refuses to do something he had previously decided to do, then this is shirk and is contrary to putting one’s trust in Allaah. He opens the door to fear and attachment to something other than Allaah. Superstition based on something that he sees or hears takes him away from the status that is expressed in the verses “You (Alone) we worship, and You (Alone) we ask for help (for each and everything)” [al-Faatihah 1:5], “So worship Him and put your trust in Him” [Hood 11:123] and “in Him I trust and unto Him I repent” [Hood 11:88]. His heart has become attached to something other than Allaah, in the sense of worship and dependence, so his heart and faith are corrupted, he will be continually disturbed by these superstitious notions and the shaytaan will lead him from that to things that will damage his religious and worldly interests. How many people have been destroyed by that and lost out in this world and in the hereafter. How can this compare to righteous optimism which brings joy to the heart, strengthens hope, quells fear, brings calm and motivates one to seek the help of Allaah and put one’s trust in Him and to be of good cheer. This is the opposite of superstition, for optimism leads a person to obey Allaah and believe in Him alone (Tawheed), whereas superstitious pessimism leads one to disobey Him and associate others with Him (shirk). Hence the Prophet (peace and blessings of Allaah be upon him) liked optimism, and he declared superstition to be invalid. 

Miftaah Daar al-Sa’aadah (2/246, 247). 

Secondly: 

In order to deal with this pessimism which the shaytaan instils by whispers and makes attractive to people: 

1 – Put your trust fully and properly in Allaah. 

It was narrated that ‘Abd-Allaah ibn Mas’ood (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Tiyarah (superstitious belief in omens) is shirk, and any one of us may think he sees an evil omen but Allaah will dispel it by means of trust in Him (tawakkul).” 

Narrated by al-Tirmidhi (1614), Abu Dawood (3910) and Ibn Majaah, (3538) 

Ibn ‘Abd al-Barr (may Allaah have mercy on him) said: 

It is proven that the Prophet (peace and blessings of Allaah be upon him) forbade tiyarah and said “There is no tiyarah.” That is because during the Jaahiliyyah they believed in superstitious omens, and he forbade them to do that and told them to put their trust in Allaah, because nothing happens except by His decree and no one has any knowledge of the unseen but Him.  

Al-Tamheed (24/195). 

2 – Go ahead with what you want to do, and do not delay it or change your mind. 

3 – Pray to Allaah to free you from this trap of the shaytaan, and ask Him for that which is good, and seek refuge with Him from evil. 

It was narrated that ‘Abd-Allaah ibn ‘Amr (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Whoever lets tiyarah (superstition) stop him from doing something has committed an act of shirk.” They said, “What is the kafaarah (expiation) for that?” He said, “To say: Allaahumma la khayra illaa khayruka wa laa tayra illaa tayruka wa laa ilaaha ghayruka (O Allaah, there is no good except Your good, no birds except Yours, and there is no god beside You).” 

Narrated by Ahmad (7045); classed as saheeh by al-Albaani in al-Silsilah al-Saheehah (3/53, hadeeth no. 1056). 

Al-Manaawi (may Allaah have mercy on him) said:  

The one who is influenced by superstitious beliefs should ask Allaah for good and seek refuge with Him from evil, and go ahead with his plans, putting his trust in Him. 

Fayd al-Qadeer (6/136). 

Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) said: 

The words “There is no good except Your good”: this is true, for all good comes from Allaah, whether it is due to a known reason or otherwise. 

The words “no birds except Yours” means: all birds belong to You, so they do not cause anything, rather they are subjugated to Your will. Allaah says (interpretation of the meaning): 

“Do they not see the birds above them, spreading out their wings and folding them in? None upholds them except the Most Gracious (Allaah). Verily, He is the All‑Seer of everything”

[al-Mulk 67:19] 

“Do they not see the birds held (flying) in the midst of the sky? None holds them but Allaah (none gave them the ability to fly but Allaah). Verily, in this are clear Ayaat (proofs and signs) for people who believe (in the Oneness of Allaah)”

[al-Nahl 16:79]

The point is that birds are subjugated to Allaah’s will and Allaah is the One Who controls them and directs them so that they fly right and left, and they have nothing to do with events that happen. 

It may be that what is meant by birds here is objects of superstition, because everything that happens to people of things they dislike comes from Allaah just as everything good comes from Allaah, as Allaah says (interpretation of the meaning): 

“Verily, their evil omens are with Allaah”

[al-A’raaf 7:131]

But we have seen above that none of the actions of Allaah can be described as bad, rather actions may seem bad to the one who is affected by them, but the action itself is not bad; rather all  His actions are all good, either good in and of themselves or because of the great good that results from them, which make them good. 

So the words “no birds except Your birds” serve to balance the words “There is no good except Your good.” 

Al-Qawl al-Mufeed Sharh Kitaab al-Tawheed (2/117, 118) and Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen (9/578). 

Shaykh Saalih al-Fawzaan (may Allaah preserve him) said: 

Superstition may be dealt with by means of these three things: 

1 – Putting one's trust in Allaah 

2 – Going ahead with one’s plans and not being influenced by it, and not allowing it to affect any of your behaviour and attitude, so it is as if it never existed. 

3 – Saying the du’aa’s mentioned in the ahaadeeth, for if you call upon Allaah with these du’aa’s, Allaah will save you from superstition and will help you and guide you. 

I’aanah al-Mustafeed Sharh Kitaab al-Tawheed (2/14).