The Meccan Revelations: Page 431 from Volume One

Sending blessings upon the Prophet in prayer and other times is a supplication from the servant who prays for Muhammad, may God bless him and grant him peace, in the unseen. It was mentioned in the Sahih on the authority of him, may the peace and blessings of God be upon him, that whoever supplicates in the back of the unseen, the kingdom will say to him, “And for you is the same,” and in a narration, “And for you is the same.”

> So the Messenger of God, may God’s prayers and peace be upon him, legislated that and God commanded it in His saying, “O you who have believed, send blessings upon him and grant him peace, so that this goodness from the kingdom would return to the one who prayed upon him from among his nation, may God bless him and grant him peace, and he commanded peace be upon him by saying, ‘And they greeted him with peace.’” So he confirmed it with the source, as it may be possible that he meant peace by that. What is mentioned in the Tashahhud, and it is possibl