Joel 2:13 - Matthew Poole's English Annotations on the Holy Bible

Rend your heart; lay them open, as chirurgeons lay open putrefying sores that they may be thoroughly cleansed; remove iniquity from your heart, as the Chaldee paraphrast. And not your garments; as hypocrites do, who in sudden or great troubles easily stoop to tear a loose garment, but hardly are brought to rend their hearts: what God expecteth most they cannot be persuaded to, but what he careth least for they are ready to do. Be not such hypocrites before God, who cannot be mocked, nor spare them who dare do it: let your garments escape if you please; but your hearts, break them, circumcise them, Deuteronomy 10:16. Turn unto the Lord your God; in repenting keep hope alive, look to God as your God, who by covenant hath promised to stow you mercy on your repenting and turning to him, Deuteronomy 13:17 Deuteronomy 30:8,9 Isaiah 55:7, Jeremiah 31:19,20 Jeremiah 32:38. He is gracious; gentle, easy to be entreated, and ready to forgive the guilty. Merciful; compassionate, and ready to show pity and relieve the indigent: you are both guilty and afflicted; return to your God, who is gracious to pardon your guilt, and merciful to relieve your miseries. Slow to anger; who hath spared, doth still spare, and waits purposely that you might have time to repent, and turn and live. Of great kindness: your provocations are many and great, yet return, for his mercy is great, his kindnesses are many. And repenteth him of the evil; not as man, but as becometh his own holy, just, and immutable nature, he turneth from executing the fierceness of his wrath, Jeremiah 18:7-10. Be wise and obedient, and follow my counsel, repent and make your peace with God.