صحيح البخاري

Narrated Abu Sa`id Al-Khudri:

We said, "O Allah's Messenger (ﷺ) This is (i.e. we know) the greeting to you; will you tell us how to send Salat on you?" He said, "Say: 'Allahumma Salli 'ala Muhammadin `Abdika wa rasulika kama sal-laita 'ala Ibrahima wa barik 'ala Muhammadin wa all Muhammadin kama barakta 'ala Ibrahima wa `Ali Ibrahim."