They asked, "Messenger of Allah, how shall we send blessings upon you?"The Messenger of Allah ﷺ replied, "Say, 'O Allah, send blessings upon Muhammad, his wives, and his descendants, as You sent blessings upon the family of Ibrahim, and bestow Your favor upon Muhammad, his wives, and his descendants, as You bestowed Your favor upon the family of Ibrahim. Indeed, You are Praiseworthy and Glorious.'"
أنهم قالوا: يا رسول الله كيف نصلي عليك؟ فقال رسول الله ﷺ قولوا: اللهم صل على محمد وأزواجه وذريته، كما صليت على آل إبراهيم، وبارك على محمد وأزواجه وذريته، كما باركت على آل إبراهيم إنك حميد مجيد.
Bukhari narrated it in the Hadiths of the Prophets (3369), and Muslim in Prayer (407-69), both through Malik bin Anas, from Abdullah bin Abu Bakr bin Muhammad bin Amr bin Hazm, from his father, from Amr bin Salim Zarqi, who said, Abu Humayd Saadi told me, and he mentioned it.I say, it has been reported by the two Shaykhs and others, as noted earlier in its place in Prayer, with the wording "and upon the family of Muhammad" instead of "his wives and his offspring," which indicates that "the family" includes them.