Albert Barnes' Notes on the Whole Bible - Psalms 50:19
Thou givest thy mouth to evil - Margin, as in Hebrew, “thou sendest.” That is, they gave it up to evil; they employed it in evil: in falsehood, malice, deceit, slander, deception, detraction.And thy tongue frameth deceit - The word rendered “frameth” means properly to bind, to fasten; and then, to contrive, to frame. The meaning is, that it was employed in the work of deceit; that is, it was employed in devising and executing purposes of fraud and falsehood. read more
The Pulpit Commentary - Psalms 50:20
Thou sittest and speakest against thy brother. Professor Cheyne understands by "brother" any fellow-Israelite; hut the parallel in the second hemistich— Thou slanderest thine own mother's son —implies that an actual brother is intended. It is one of the special characteristics of the reprobate to be "without natural affection" ( Romans 1:31 ). read more