Commentary for Job 6:14

By one who withholds kindness from his friend Heb. למס, by one who withholds kindness. The “lammed” is a prefix, as in (Num. 26:54), “to the numerous one (לָרַב)”; “to the one who returns (?) (לָשָב),” and (Isa. 28:10, 13) “for a precept (לצו).” מָס too is an expression of a verb, like בָּא, comes: שָב, returns; גָר, dwells; these also are an expression of doing [i.e., the present tense]:

who withholds kindness, who destroys it, like (Exod. 16:21), “when the sun grew hot, it melted (ונמס).”