Numbers 23:20

And Balaam said unto Balak, Build me here seven altars, and prepare me here seven oxen and seven rams.

And Balak did as Balaam had spoken; and Balak and Balaam offered on every altar a bullock and a ram.

And Balaam said unto Balak, Stand by thy burnt offering, and I will go: peradventure the LORD will come to meet me: and whatsoever he sheweth me I will tell thee. And he went to an high place.

And God met Balaam: and he said unto him, I have prepared seven altars, and I have offered upon every altar a bullock and a ram.