Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 320
Narrated Ka'b bin Ujra:
It was said, "O Allah's Apostle! We know how to greet you, but how to invoke Allah for you?" The Prophet said, "Say: Allahumma salli ala Muhammadin wa'ala Ali Muhammaddin, kama sallaita 'ala all Ibrahim, innaka Hamidun Majid."