Virtues of Surah Yasin: What Are They?
Question

Are there any saheeh ahaadeeth which speak of the virtues of reading Soorat Ya-Seen? Some people say that Ya-Seen is for that for which it is read, is this correct?
Praise be to Allah.Firstly: 
What is Surah Ya-Sin?
Surah Ya-Sin is one of the Makkan surahs of the Quran, containing eighty-three verses, with frequent pauses and short phrases which has a strong effect on the believing soul. 
What is the subject matter of Surah Ya-Sin?
The main subject matter of Surah Ya-Sin is the same as other Makkan surahs; it speaks of Tawhid al-uluhiyyah and Tawhid al-rububiyyah (the Oneness of Allah and of His Lordship) and the punishment for those who disbelieve in that. The issue that is focused on in this surah is the issue of the Resurrection. 
Hadiths about the virtues of Surah Ya-Sin: Authentic?
There are a number of ahadith which speak of the virtues of this surah, most of which are, however, false and fabricated, and some of which are slightly weak (da’if). We have not found any sahih hadith which speaks specifically of the virtues of Surah Ya-Sin. 
Examples of hadiths about the virtues of Surah Ya-Sin
Among the reports which have been narrated concerning its virtues but classed as da’if by the scholars of hadith include the following, which we are only quoting here to warn about them: 
“Everything has a heart, and the heart of the Quran is Ya-Sin; whoever reads it, it is as if he has read the Quran ten times.”
“Whoever reads Surah Ya-Sin in one night will be forgiven in the morning.”
“Whoever continues to read it every night then dies, will die as a shahid (martyr).”
“Whoever enters the graveyard and reads Surah Ya-Sin, their (punishment) will be reduced that day, and he will have hasanat (reward) equal to the number of people in the graveyard.” See: al-Mawdu’at by Ibn al-Jawzi (2/313); al-Fawaid al-Majmu’ah by al-Shawkani (979, 942). See also the essay Hadith Qalb al-Quran Ya-Sin fi’l-Mizan wa Jumlat mimma ruwiya fi Fadailiha by Shaykh Muhammad ‘Amr ‘Abd al-Latif, may Allah preserve him. 
Please see also questions no. 654  and 6460 . 
‘Ya-Sin is for that for which it is read’: Is it an authentic hadith?
Some people narrate a hadith which says “Ya-Sin is for that for which it is read,” meaning that reading Surah Ya-Sin may cause needs to be met and may make things easier, according to the intention of the reader when he reads it. 
We must note that it is incorrect to attribute these words to the Sunnah of the Prophet (peace and blessings of Allaah be upon him) or to any of the scholars among the Sahabah, Tabi'in or imams. No such words have been narrated from any of them, rather they pointed out that this is false. 
Al-Sakhawi (may Allah have mercy on him) said of this hadith: 
“There is no basis for this version.” Al-Maqasid al-Hasanah (741). Al-Qadi Zakariyya said in Hashiyat al-Baydawi: it is mawdu’ (fabricated), as it says in Kashf al-Khafa (2/2215). 
Something similar appears in al-Shadharah fi’l-Ahadith al-Mushtaharah by Ibn Tulun al-Salihi (2/1158) and in al-Asrar al-Marfu’ah by al-Qari (619), and elsewhere. See the essay by Shaykh Muhammad ‘Amr referred to above, Hadith Qalb al-Quran Ya-Sin …, p. 80. 
It is not permissible for anyone to attribute this hadith to the Prophet (peace and blessings of Allah be upon him) or to speak of it in people’s gatherings. Whoever claims that experience shows this hadith to be true should be told: Experience also shows that for many of those who read Ya-Sin to have their needs met, Allah did not meet their needs, so why should we accept your experience and not the experience of others?  
What Imam Ibn Kathir quoted in Tafsir al-Quran il-‘Azim (3/742) from some of the scholars, that one of the qualities of this surah is that “it is never recited in the event of some difficult matter but Allah makes it easy” is ijtihad on their part, for which there is no evidence from the Quran or Sunnah, or from the words of the Sahabah or Tabi'in. Such ijtihad cannot be attributed to Allah or His Messenger, rather it can only be attributed to the one who said it, who may be right or wrong. It is not permissible to attribute to the Book of Allah or the Sunnah of His Messenger anything but that which we are certain is part of it. Allah says (interpretation of the meaning): 
“Say (O Muhammad): (But) the things that my Lord has indeed forbidden are Al-Fawahish (great evil sins and every kind of unlawful sexual intercourse) whether committed openly or secretly, sins (of all kinds), unrighteous oppression, joining partners (in worship) with Allah for which He has given no authority, and saying things about Allah of which you have no knowledge” [al-A’raf 7:33]
What about those whose needs are met when they read Surah Ya-Sin?
We should point out here that many of those whose needs are met when they call upon Allah (du’a) or recite such verses, have their needs met because of the humility and need for Allah that they feel in their hearts, and their sincere turning to Him, not because of the du’a that they recited or the du’a that they offered beside a grave, and so on. 
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
“The reason why the needs of some of those who offered haram du’as are  met is that one of them may be in desperate need, such that even if a mushrik were in that state, praying beside an idol, he would receive a response, because of his sincere turning to Allah, even though saying du’a beside the idol is shirk, even if his need is met by means of the one that he is taking as a mediator with Allah, whether it is the occupant of the grave or someone else, still  he will be punished for that and will be thrown into Hell, if Allah does not forgive him. 
Then he said: Hence many people get it wrong, because they hear about some prominent righteous people did an act of worship or recited a certain du’a and they found that that act or worship or du’a had an effect, so they took that as evidence that this act of worship or du’a is something good to do, and they regard that action as a Sunnah, as if a prophet had done it. This is a mistake for the reasons we have mentioned above, especially since the effects of that action only came as the result of sincerity in the person’s heart when he did it, then his followers do it without sincerity, so they are harmed by it, because this action is not prescribed, so they do not attain the reward for following, and they do not have the same sincerity as the first one did, who may be forgiven because of his sincerity and sound intention.” (Iqtida al-Sirat al-Mustaqim (2/698, 700) 
And Allah knows best.