תהלים נה:כב
חָלְק֤וּ ׀ מַחְמָאֹ֣ת פִּיו֮ וּֽקֲרָב־לִ֫בּ֥וֹ רַכּ֖וּ דְבָרָ֥יו מִשֶּׁ֗מֶן וְהֵ֣מָּה פְתִחֽוֹת:

KJV: The words of his mouth were smoother than butter, but war was in his heart: his words were softer than oil, yet were they drawn swords.

This seems to be the etymology of the modern Hebrew מחמאה, compliment or flattery