(527) بَابُ صَدْرِ الرَّسَائِلِ: بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ
Abu Mas'ud al-Jurayri related to him that a man asked al-Hasanabout reading, "In the Name of Allah, the All-Merciful, Most Merciful."He said, "That should be put at the beginning of letters."
Reference: Al-Adab Al-Mufrad 1123
In-book reference: Book 45, Hadith 7
English translation: Book 45, Hadith 1123