They asked the Messenger of Allah ﷺ, "How shall we send blessings upon you?"He replied, "Say, 'O Allah, send blessings upon Muhammad and bless Muhammad and the family of Muhammad, just as You sent blessings and blessed Ibrahim and the family of Ibrahim among the worlds. Indeed, You are Praiseworthy, Glorious.' And the salutation is as you have already been taught."
سألوا رسول الله ﷺ كيف نصلي عليك؟ قال: قولوا: اللهم صل على محمد وبارك على محمد وعلى آل محمد، كما صليت وباركت على إبراهيم وآل إبراهيم في العالمين، إنك حميد مجيد، والسلام كما علمتم.
Bazzar narrated it in Kashf Astar (565), Ahmad bin Abdah told us, Salim bin Akhdar informed us, Dawud bin Qays narrated to us, from Naim, from Abu Hurairah, and he related the hadith. Bazzar said, "We do not know it except through the hadith of Dawud, from Naim, from Abu Hurairah."I say, Dawud bin Qays is al-Farra al-Dabbagh, and his being the sole transmitter does not harm the hadith, for he is trustworthy. Ahmad, Abu Zura, Nasai, and others deemed him trustworthy, and he is among the narrators of Muslim.Naim is Ibn Abdullah al-Mujmir, Abu Abdullah al-Madani, the freedman of the family of Umar bin Khattab. He used to perfume the masjid with incense, and he is trustworthy, narrated from by the group of hadith compilers. This is why Haythami said in Majma al-Zawaid (2870), "Bazzar narrated it, and its narrators are the narrators of the sahih."Hafiz said in Nataij Afkar (2/208), "This is a sahih hadith, Bazzar extracted it from Ahmad bin Abdah through this chain," and he commented on Bazzar's statement, saying, "Its narrators are the narrators of the sahih."