Numbers 23:27-30
23:27 Balak said to Balaam, “Come, please; I will take you to another place. Perhaps it will please God to let you curse them for me from there.”
23:28 So Balak took Balaam to the top of Peor, that looks toward the wilderness.
23:29 Then Balaam said to Balak, “Build seven altars here for me, and prepare seven bulls and seven rams.”
23:30 So Balak did as Balaam had said, and offered a bull and a ram on each altar.