Dict: easton - Reins

easton:

Reins @ the kidneys, the supposed seat of the desires and affections; used metaphorically for "heart." The "reins" and the "heart" are often mentioned together, as denoting the whole moral constitution of man kjv@Psalms:7:9 kjv@Psalms:16:7 kjv@Psalms:26:2 ; 139:13; kjv@Jeremiah:17:10, etc.).