Genesis 12:7-8

7The Lord appeared to Abram there. He said, ‘I will give this land to your descendants.’ So Abram built an altar in that place to worship the Lord. He did that because the Lord had appeared to him.

8Then Abram left Shechem. He went to the hills that are on the east of Bethel. He put up his tent in that place. Bethel was towards the west, and Ai was towards the east. Abram also built an altar there to worship the Lord.