The Messenger of Allah (ﷺ) came one day with a cheerful expression on his face, and we said: "We see you looking cheerful". He said: "The Angel came to me and said: 'O Muhammad, your Lord says: 'Will it not please you (to know) that no one will send salah upon you that I will send salah upon him tenfold, and no one will send salams upon you but I will send salams upon him tenfold?'"
Sunan an-Nasa'i Book 13, Hadith 105