Verse 1of 30

Which was revealed in Al-MadinahThe Virtues of Surah Alif Lam Mim As-SajdahIn the Book of the Friday prayer, Al-Bukhari recorded that Abu Hurayrah said, "The Prophet used to recite in Fajr on Fridays:الم تَنزِيلَ(Alif Lam Mim. The revelation of...), As-Sajdah, andهَلْ أَتَى عَلَى الإِنسَـنِ(Has there not been over man...)Al-Insan (76)." This was also recorded by Muslim. Imam Ahmad recorded that Jabir said, "The Prophet would never sleep until he recited:الم تَنزِيلَ(Alif Lam Mim.

Source: Tafsir Ibn Kathir — abridged excerpt