pat on the back
pat on the back (2) {n. phr.}
1. An encouraging tap of the hand on someone's back; a show of sympathy or support.
I gave her a pat on the back and told her she had done fine work.
2. A word or gesture of praise or other encouragement; applause.
Pats on the back weren't enough; he wanted hard cash.
Categories:
Source: A Dictionary of American Idioms