Reins a name for the kidneys, derived from the Latin renes, and in our English Bible employed in those passages of the Old Test. in which the ierm for kidneys (כּלָיוֹת, kelayoth) is used metaphorically, i.e. except in the Pentateuch and in Isa 34:6, where this word is rendered "kidneys." In the ancient system of physiology the kidneys, from the sensitiveness of that part of the person, were believed to be the seat of desire and longing, which accounts for their often being coupled with the heart (Ps 7:9; Ps 26:2; Jer 11:20; Jer 17:10,: etc.). SEE KIDNEYS.
The word "reins" is once used (Isa 11:5) as the equivalent of חֲלָצָיַם, chalatsayim, elsewhere translated "loins" (q.v.).