Joel
Joel 2:13ESV·traditional attribution

and rend your hearts and not your garments.” Return to the LORD your God, for he is gracious and merciful, slow to anger, and abounding in steadfast love; and he relents over disaster.

John Calvin Reformed @genevareformer

He then subjoins, Rend your heart, and not your garments, and turn to Jehovah your God. The Prophet again repeats that we ought to deal sincerely with God; for all those ceremonies, by which men imagine that they discharge their duties, are mere mockeries, when they are not preceded by a pure and sincere heart.

Matthew Henry Presbyterian @wholebiblehenry

We have here an earnest exhortation to repentance, inferred from that desolating judgment described and threatened in the foregoing verses: Therefore now turn you to the Lord. 1. "Thus you must answer the end and intention of the judgment; for it was sent for this end, to convince you of your sins, to humble you for them, to reduce you to your right minds and...

Commenting on Joel 2:12-17

John Gill Reformed Baptist @doctorgill

And rend your heart, and not your garments,.... Which latter used to be done in times of distress, either private or public, and as a token of grief and sorrow, Gen 37:34; nor was it criminal or unlawful, the apostles themselves used it, Act 14:14; nor is it absolutely forbidden here, only comparatively, that they should rend their hearts rather than their garments; or not...