Joel reuses the Exodus 34 proclamation that YHWH is gracious, merciful, slow to anger, and abundant in steadfast mercy as the basis for calling sinners to return. The prophet’s appeal to repentance therefore rests on the character God had already revealed to Moses.

Jonah 4:2 and Joel 2:13 both reuse the Exodus 34 description of YHWH as gracious, merciful, slow to anger, abundant in mercy, and one who relents from disaster.

Joel calls for fasting and a turn to YHWH and asks, “Who knoweth if he will return and repent”; Nineveh fasts, turns from evil, and asks, “Who can tell if God will turn and repent?”

Deuteronomy 30 promises mercy and restoration when God’s people return to him with all heart and soul after covenant curse; Joel summons the people to return to the LORD with all their heart.