Judges 6:26
And build an altar unto the LORD thy God upon the top of this rock, in the ordered place, and take the second bullock, and offer a burnt sacrifice with the wood of the grove which thou shalt cut down. And build an altar unto the LORD thy God upon the top of this rock, in the ordered place, and take the second bullock, and offer a burnt sacrifice with the wood of the grove which thou shalt cut down.
Israel's sins had separated them from God and brought them into subjection under Midianite oppression, and after the people confessed their sins God raised up a faithful and valiant deliverer to put down idolatry and free them from their enemies. This belongs to the time of that oppression and that confession, when a helper was raised up for Israel. It illustrates the repeated story of backsliding and chastisement followed by confession and deliverance, in which after the deliverer died and the people were released from his authority they gradually returned to their idols.
Gideon was commanded to tear down Baal's altar and to build an altar to the Lord on the top of the rock where the earlier offering had been consumed, in place of the false altar. There he was to take the second bullock and offer it as a burnt sacrifice using the wood of the grove he cut down. Although sacrifice had been restricted to the altar at Shiloh and to priests and Levites, God who established the ritual service and to whom the offerings pointed had authority to change its requirements and to authorize this departure.
The destruction of Baal's altar and the offering of the sacrifice had to come before Israel's battle against Midian and its other enemies. It was a solemn public protest against Baal worship and idolatry and an acknowledgment of Jehovah as the only true and living God. God's work against idolatry in this way includes establishing worship of the Lord where false worship had been practiced. The bullock poised between sacrifice and plowing represents the choice God's people must be ready to make to serve God actively rather than remain idle and self-indulgent. Those called to the same kind of duty to reprove sin and tear down idolatrous images must act promptly and courageously, yet never use the work to indulge harshness or personal feelings.