This is a ‘madani’ surah and it has 37 ayaat. In the commentary of Majma’ul Bayan it is narrated that the Holy Prophet (s.a.w.) said that whoever recites this surah will have his thirst quenched by the drink from the rivers of Jannah.
Imam Ja’far as-Sadiq (a.s.) said that the person who recites this surah will never have doubts about his religion and will not fall into disbelief and Shirk. A thousand angels will send salutations to his grave after his death. He will be placed under the protection of Allah (s.w.t.) and His Prophet (s.a.w.). When the reciter of this surah will arise from his grave, whichever way he turns, he will see the blessed face of the Holy Prophet (s.a.w.).
If this surah is written and kept as a talisman, it protects a person, whether he is asleep or awake, from all evils and problems. It is also a safety from insanity.