If we were to give an exhaustive account of the benefits of the recitation of “Bismillah…” we would need more than a single volume to do justice to it. Apart from being part of every chapter in the Holy Qur’an (except the chapter of repentance [surah at-tawba]), it is also the most oft repeated verse in the Holy Qur’an.
It is narrated in Tafseere Burhaan that the Holy Prophet (s.a.w.) has said that when a person recites “Bismillah...” then five thousand ruby palaces are built for him in Jannah Each palace has a thousand chambers made of pearls and in each chamber has seventy thousand thrones of emerald and each throne has seventy thousand carpets made from special fabrics and upon each carpet is seated a Hur-ul-Ein. A person asked for the condition necessary to get this great reward and the Holy Prophet (s.a.w.) replied that the person should recite the “Bismillah…” with conviction and understanding. You can judge how many merits complete Quran Recitation may have from this narration.
The Holy Prophet (s.a.w.) has also said that when a believer will have to cross the Pul-e-Siraat on the Day of Judgement, and he will say “Bismillah…” then the flames beneath him will start dying down until Jahannam will cry out, ‘O believer, pass through quickly, your presence is causing my fire to die out !’
In Islamic Schools the first lesson given to a child is to recite “Bismillah” knowing the fact that when a teacher teaches a child to recite “Bismillah…” the child, his parents and the teacher are all guaranteed freedom from hellfire. It is narrated that Prophet Isa (a.s.) was once passing by a graveyard and he saw a grave upon which the Wrath and Punishment of Allah (s.w.t.) was descending, so he quietly walked past. When he passed the same place after some time, he noticed that the Mercy and Blessings of Allah (s.w.t.) was being showered on the same grave. He was surprised at this and asked Allah (s.w.t.) about what has happened and it was revealed to him that the man inside the grave was a sinner and was thus being punished for his sins. When he died, his wife was pregnant and soon gave birth to a son. When the boy grew older, his mother took him to a teacher who taught him to recite “Bismillah…” and I felt that it would not be justice that this man’s son was calling My Name and I was punishing his father in the grave.
It is also mentioned that recitation of “Bismillah…” with a loud voice is from the signs of a true believer. Imam Ali Ridha (a.s.) said that “Bismillah…” is very close to the chosen name of Allah (s.w.t.) [Isma A’adham].