Read Jeremiah 34:1-22
Babylon had laid siege to Jerusalem, and the city was about to fall. Zedekiah finally decided to listen to Jeremiah and try to appease God: so he freed the slaves. He thought he could win God’s favor with a kind act, but what he needed was a change of heart. The people had been disobeying God’s law from the beginning (Exodus 21; Leviticus 25; Deuteronomy 15). When the siege was temporarily lifted, the people became bold and returned to their sins.
The people of Israel had a hard time keeping their promises to God. In the Temple, they would solemnly promise to obey God, but back in their homes and at work they wouldn’t do it. God expressed His great displeasure. If you want to please God, make sure you keep your promises. God wants promises kept, not just piously made.
Cutting a calf in two and walking between the halves was a customary way to ratify a contract (Genesis 15). This action symbolized the judgment on anyone who broke the contract. God was saying, “You have broken the contract you made with Me, so you know the judgment awaiting you.”