One good turn deserves another - Cultural Definition
The New Dictionary of Cultural Literacy Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A kindness is properly met with another kindness.
one good turn deserves another - Phrases/Idioms
A favor should be returned in kind, as in I'll give you a ride next time—one good turn deserves another. This maxim was first recorded about 1400, and the converse, One bad turn deserves another, about 1500.