Should people tear their clothes in grief and repentance, or not?

Joel is not banning the custom. He uses a Hebrew way of speaking in which ‘not this, but that’ means ‘not this only, but above all that’. The verse before shows it: in the same breath God calls for “fasting, and with weeping, and with mourning” (Joel 2:12), all of them outward signs of grief. Hosea uses the same form: “For I desired mercy, and not sacrifice” (Hosea 6:6), although God himself had commanded the sacrifices. The point is what matters most. Torn clothes without a broken heart are an empty show; what God looks for is “a broken and a contrite heart” (Psalm 51:17). Gill puts it that Joel forbids the outward sign not absolutely but only comparatively.

Josiah shows the two together, which is just what Joel asks for. God heard him “Because thine heart was tender, and thou hast humbled thyself” and because he had “rent thy clothes, and wept” (2 Kings 22:19). His torn clothes expressed real sorrow at God’s word, and God honoured both. Ecclesiastes 3:7 simply observes that life has its seasons: a time for tearing clothes, as in mourning, and a time for sewing them up again. Godly people did tear their clothes in Scripture, among them Jacob (Genesis 37:34), Hezekiah (2 Kings 19:1), and Paul and Barnabas when the crowd at Lystra tried to worship them (Acts 14:14).

Elisha’s question is not about clothes at all. The king of Israel tore his clothes in panic, because he thought the king of Syria was picking a quarrel with him by asking for a leper to be healed (2 Kings 5:7). He forgot that God had a prophet in Israel. Elisha’s answer shows what was wrong: “let him come now to me, and he shall know that there is a prophet in Israel” (5:8). The rebuke was for despair and unbelief, not for the gesture. So the passages agree: an outward sign of grief has its place, but never in place of the heart.