pay a compliment
Express praise or commendation to someone, as in Meredith wanted to pay Christopher a compliment so she told him she liked his new haircut. This expression uses pay in the sense of “give something that is due.” [c. 1700]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.