Narrated Abu Sa`id Al-Khudri:
We said, "O Allah's Messenger (ﷺ)! (We know) this greeting (to you) but how shall we invoke Allah for you?" He said, "Say! Allahumma salli ala Muhammadin `Abdika wa rasulika kama- sallaita 'ala all Ibrahim wa barik ala Muhammadin wa'ala all Muhammadin kama barakta 'ala all Ibrahim.' Al-Laith said: 'Ala Muhammadin wa 'ala all Muhammadin kama barakta ala all Ibrahim.Narrated Ibn Abi Hazim and Ad-Darawardi:Yazid said, "Kama sallaita ala Ibrahima wa barik 'ala Muhammad in wa all Muhammadin kama barakta 'ala Abrahima wa all Ibrahim." (DE)
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 321 (DE)
Arabic reference (DE): Book 65, Hadith 4798 (DE)