Matthew Poole and continuators on Proverbs 25:19

19 Confidence in an unfaithful man in time of trouble, is like a broken tooth and a foot out of joynt .

It is not onely deceitful, but hurtful, as a broken Tooth though it make shew of helping, yet is not onely unhelpful to a Man for chewing his Meat, but also troublesome and painful; and as a Foot out of Joynt, doth not help but hinder, and pain him that attempts to walk upon it.