Upon the top of this rock; of which Jud_6:20,21. Heb. of this strong hold; for in that calamitous time the Israelites retreated to such rocks, and hid and fortified themselves in them.
In the ordered place, i.e. in a plain and smooth part of the rock, where an altar may be conveniently built. Or,
in order, i.e. in such manner as I have appointed; for God had given rules about the building of altars.
Offer a burnt-sacrifice: Gideon was no priest, nor was this the appointed place of sacrifice; but God can dispense with his own institutions, though we may not; and his call gave Gideon sufficient authority.