God's directive to Gideon initiates a dramatic spiritual and physical transformation. He is instructed to dismantle the familiar symbols of idol worship from his father's house and repurpose them to build an altar and offer a sacrifice to God. This bold act is designed to expose the absolute worthlessness of the idols and firmly establish Gideon's faith.
The primary approach among commentators is that the designated location for this new altar is a strong, towering rock—specifically, the very same rock where Gideon had previously placed meat and unleavened bread [רש״י, מצודת דוד, מצודת ציון, רד״ק, רלב״ג, ביאור שטיינזלץ]. A different perspective suggests the command refers to the strength of the first altar already built upon that rock. According to this view, Gideon must construct a second altar on top of the first, using the stones salvaged from the demolished altar of Baal [מלבי״ם]. In either case, the construction must take place on a flat, organized, and prepared surface at the top of the rock [מצודת דוד, מצודת ציון, רד״ק, רלב״ג, ביאור שטיינזלץ], or directly upon the arrangement where the initial sacrifice was offered [מלבי״ם].
For the sacrifice itself, Gideon is told to take a specific bull belonging to his father. Seizing this animal effectively prevents it from being used in idol worship [מצודת דוד]. This bull carries deep symbolic weight. It had been set aside for pagan rituals for exactly seven years, perfectly mirroring the seven years the Israelites suffered under Midianite oppression due to their idolatry. By taking this specific bull and offering it to God, Gideon atones for the collective sins of that entire period [אלשיך]. Alternatively, another view suggests it may simply be a regular bull with no prior connection to pagan worship [אלשיך].
The sacrifice is to be burned using the wood of the Asherah tree. Wood that was once worshipped as an idol is now reduced to mere fuel for God's altar [מצודת דוד]. By stripping the pagan stones, the worshipped wood, and the designated bull of their impurity and transforming them into holy instruments, the event powerfully proves the powerlessness of idols and inspires Gideon toward profound self-sacrifice for God [מלבי״ם].
To carry out this extraordinary event, Gideon is granted a special, temporary exemption from standard religious law. Several severe prohibitions are suspended for that single night: a non-priest is permitted to offer a sacrifice, the offering takes place outside the Tabernacle, it is performed at night, and it utilizes animals and wood previously dedicated to idolatry. The ultimate purpose of this unprecedented directive is to show Gideon that acting in direct defiance of the pagan culture of his youth is precisely what will guarantee his success and salvation, deeply reinforcing his faith in God [רלב״ג, מלבי״ם].