תהילים נה:כב פירוש: רש״י

Smooth were Heb. חלקו, an expression of (above 35:6): “and slippery (וחלקלקות).”

the buttery words of his mouth Heb. מחמאת, an expression of חמאה butter. The first “mem” is a defective radical in the word, like the “mem” of מעשה and the “mem” of מאמר.

but his heart was set on war Heb. וקרב, to war.