The Prophet (ﷺ) said: "Whoever sends salah upon me once, Allah (SWT) will send salah upon him tenfold."
Sunan an-Nasa'i Book 13, Hadith 118
← Previous Hadith The Messenger of Allah (ﷺ) came one day with a joyful expression on his face. He said: "Jibril came to me and said: 'Will it not please you, O Muhammad, (to know) that no one of your Ummah will send salah upon you but 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 117 Next Hadith → "The Messenger of Allah (ﷺ) said: "Whoever sends salah upon me once, Allah (SWT) will send salah upon him tenfold, and will erase ten sins from him, and will raise him ten degrees in status."

Sunan an-Nasa'i Book 13, Hadith 119