Proverbs 29:5

A man who flatters his neighbor spreads a net for his feet.

Proverbs 26:23-28

Whoever hates disguises himself with his lips and harbors deceit in his heart; when he speaks graciously, believe him not, for there are seven abominations in his heart; though his hatred be covered with deception, his wickedness will be exposed in the assembly. Whoever digs a pit will fall into it, and a stone will come back on him who starts it rolling. A lying tongue hates its victims, and a flattering mouth works ruin.

Proverbs 28:23

Whoever rebukes a man will afterward find more favor than he who flatters with his tongue.