ap'-e-tit (chai, nephesh): This word occurs four times in Old Testament text and once in the King James Version margin. Once (Job 38:39) it is a translation of chai, "life"; "Canst thou .... satisfy the appetite (life) of the young lions?" Twice (Pr 23:2; Ec 6:7; also Isa 56:11, the King James Version margin) it is a translation of nephesh: Pr 23:2, ba`al nephesh "a man given to appetite"; Ec 6:7, "the nephesh is not filled." In Isa 56:11, "strong of nephesh" is translated "greedy." Nephesh means originally "breath," hence "the soul," psuche, "the vital principle," "life"; therefore in certain expressions referring to the sustaining of life the nephesh hungers (Pr 10:3), thirsts (Pr 25:25), fasts (Ps 69:10). Nephesh then comes to mean the seat of the senses, affections, emotions, and to it is ascribed love, joy, desire (compare De 12:20; Pr 6:30 the Revised Version, margin; Mic 7:1, where the nephesh "desires"). The idea of desire or appetite of the nephesh may include all forms of longing; e.g. lust (Jer 2:24; "her desire" is literally "the desire of her nephesh"), the appetite for revenge (Ps 41:2, "the will of his enemies" is literally "the nephesh," etc.). The next step is to identify the nephesh with its desire, hence in the cases above nephesh is translated "appetite." In the 4th case (Isa 29:8) "His soul hath appetite" is a free translation of naphsho shoqeqah, literally "His soul runneth to and fro."
S. F. Hunter