The Messenger of Allah (ﷺ) said: He who blesses me once, Allah would bless him ten times.
Sahih Muslim Book 4, Hadith 74
← Previous Hadith They (the Companions of the Holy Prophet) said: Apostle of Allah, how should we bless you? He (the Holy Prophet) observed: Say:" O Allah! bless Muhammad, his wives and his offspring as Thou didst bless Ibrahim, and grant favours to Muhammad, and his wives and his offspring as Thou didst grant favours to the family of Ibrahim; Thou art Praiseworthy and Glorious."

Sahih Muslim Book 4, Hadith 73 Next Hadith → The Messenger of Allah (ﷺ) said: When the Imam says:" Allah listens to him who praises Him." you should say:" O Allah, our Lord for Thee is the praise." for if what anyone says synchronises with what the angels say, his past sins will be forgiven.

Sahih Muslim Book 4, Hadith 75