What does Judges 6:26 mean?
After Gideon's challenging and reassuring interaction with the Lord (Judges 6:11–23), he built an altar to God under the tree where they met (Judges 6:24). The Lord came to Gideon that very night and commanded him to destroy an altar to Baal and a "sacred" Asherah pole beside it. Both were used for the worship of false Canaanite gods (Judges 3:7). Both stand on the property of Gideon's father, Joash.In addition, Gideon is to build a replacement altar—a legitimate altar—to God. This is to be placed on top of the stronghold and built with stones laid in a specific order. This altar to the "Lord your God" will replace the altar to Baal. The Asherah pole Gideon cuts down is to be used as fuel for the fire on the new altar. God is not merely commanding Gideon to remove the pagan artifacts, but to destroy them and replace them with godly alternatives.
Finally, Gideon must sacrifice a seven-year-old bull from his father's herd on that altar to Yahweh. This is the second bull mentioned. Gideon was apparently meant to use the first one to pull down the Baal altar.
Gideon will comply, but with as much caution and secrecy as was possible for such a dramatic task (Judges 6:27).