Thomas Aquinas Commentary Jeremiah 12:13

"They have sown wheat, and have reaped thorns; they have put themselves to pain, and profit nothing: and ye shall be ashamed of your fruits, because of the fierce anger of Jehovah." — Jeremiah 12:13 (ASV)

Here, he threatens the punishment of sterility.

1. The futility of the seed: they have sown. It is as though he were saying, “The seeds will be corrupted.” Did you not sow good seed in your field? (Matthew 13:27). I waited for it to produce grapes, and it brought forth wild grapes (Isaiah 5:4).
2. The loss of their inheritance: they have received an inheritance, and it did not profit them, because it was stolen by the enemy. Our inheritance has been turned over to strangers (Lamentations 5:2).
3. He introduces shame: you shall be ashamed, because of the failing of your crops. The vintage has mourned, the vine is weakened, and all who were joyful in heart have sighed (Isaiah 24:7).