Judges 6:26-27

26and build an altar to the Lord your God on the top of the stronghold here, with stones laid in due order. Then take the second bull and offer it as a burnt offering with the wood of the Asherah that you shall cut down."

27So Gideon took ten men of his servants and did as the Lord had told him. But because he was too afraid of his family and the men of the town to do it by day, he did it by night.