John Gills Exposition of the Bible Commentary - Proverbs 10:18
He that hideth hatred with lying lips ,.... Or he whose "lying lips hide hatred", which is much the same; who pretends to be a friend, and outwardly behaves as one, but inwardly nourishes and cherishes hatred in his heart, which he covers and conceals, till he has a proper opportunity of showing it; as Absalom to Ammon, Joab to Amasa, the men of Anathoth to Jeremiah, and Judas to Christ; see Proverbs 26:24 . Or, "he that hideth hatred is a man of lying lips" F13 "Est vir laborium... read more
Matthew Henry's Complete Commentary - Proverbs 10:18
Observe here, Malice is folly and wickedness. 1. It is so when it is concealed by flattery and dissimulation: He is a fool, though he may think himself a politician, that hides hatred with lying lips, lest, if it break out, he should be ashamed before men and should lose the opportunity of gratifying his malice. Lying lips are bad enough of themselves, but have a peculiar malignity in them when they are made a cloak of maliciousness. But he is a fool who thinks to hide any thing from God. 2.... read more