Their being covered with such a heavy layer of fat made kidneys a specially precious part of the animal sacrifices that Jehovah’s people anciently offered to him.

Also, regarding the sacrifices to be offered to Jehovah by the Israelites, we read repeatedly of “the two kidneys and the fat that is upon them” as being assigned to Jehovah. (Lev. 3:4, 10, 15; 4:9; 7:4; 8:16) Kidney fat burned well and produced a pleasing odor. So kidneys were no insignificant part of sacrifices to God.