en_tn_lite_do_not_use/jas/05/05.md

You have fattened your hearts for a day of slaughter

Here people are viewed as if they were cattle, luxuriously fed on grain so they would become fattened to be slaughtered for a feast. However, no one will feast at the time of judgment. Alternate translation: "Your greed has only prepared you for harsh eternal judgment" (See: rc://en/ta/man/jit/figs-metaphor)

your hearts

The "heart" was considered to be the center of human desire, and here stands for the entire person. (See: rc://en/ta/man/jit/figs-metonymy)