The altar was constructed on the same foundations as the altar used before the exile in order to make sure it was on the one true spot for the worship of the Lord.1 The Lord had told David where the altar was to be built (2 Samuel 24:18). The exiles wanted to build it on the same place.
3 They set the altar in its place, for fear was on them because of the peoples of the lands, and they offered burnt offerings on it to the LORD, burnt offerings morning and evening.