We said, "Messenger of Allah, this is how we send peace upon you, but how should we send blessings?"He replied, "Say, 'O Allah, send blessings upon Muhammad, Your servant and Messenger, as You sent blessings upon Ibrahim, and bless Muhammad and the family of Muhammad as You blessed Ibrahim and the family of Ibrahim.'"
قلنا يا رسول الله: هذا السلام عليك، فكيف نصلي؟ قال: قولوا: اللهم صل على محمد عبدك ورسولك، كما صليت على إبراهيم، وبارك على محمد وعلى آل محمد كما باركت على إبراهيم وآل إبراهيم.
Bukhari narrated it in "Supplications" (6358) from Ibrahim bin Hamza, who said, Ibn Abu Hazim and Darawardi narrated to us, from Yazid (that is, Ibn Hadi), from Abdullah bin Khabab, from Abu Saeed, and he mentioned it.