21 As charcoal is to hot embers and wood to fire, so is a quarrelsome person for kindling strife.

Matthew Henry's Commentary on Proverbs 26:21

Commentary on Proverbs 26:20-22

(Read Proverbs 26:20-22)

Contention heats the spirit, and puts families and societies into a flame. And that fire is commonly kindled and kept burning by whisperers and backbiters.