Albert Barnes Commentary Jeremiah 14:12

"When they fast, I will not hear their cry; and when they offer burnt-offering and meal-offering, I will not accept them; but I will consume them by the sword, and by the famine, and by the pestilence." — Jeremiah 14:12 (ASV)

Their cry (that is) – prayer offered aloud.

Oblation – A meat-offering (Leviticus 2:1).

The sword, famine, and pestilence – The latter two always follow the first (Ezekiel 5:12), and through these God will consume them, yet so as to leave a remnant. The chastisement, which crushes those who harden themselves against it, purifies the penitent.