Opens the quarrels, gossip and deceiver run, Proverbs 26:17–28, twelve verses. The cluster is thematic; each verse stands alone.
Quick answer
Grabbing a stray dog's ears is easy and letting go is not. The verse is about the moment after you involve yourself.
Read both lines
Every word of the first line matters. He passes by, so he was not involved and was going somewhere else; he meddles, an active insertion; and the quarrel is explicitly not his own. The saying is not about mediation, which this book values, and not about defending someone who cannot defend themselves, which it commands at 24:11 and 31:8. It is about a bystander who reaches in.
Then the image supplies the trap. Seizing a dog by the ears is the easy half, and the hard half is what you do next, since you cannot safely hold on and cannot safely release. That is the position a meddler occupies almost immediately: both parties now have a reason to turn on him, and the exit he wanted was available only before he reached.
Related: Proverbs 20:3 · Proverbs 17:14 · Proverbs 24:11 · Proverbs 18:6
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.