‘And he removed from there to the mountain on the east of Bethel (‘house of God'), and pitched his tent, having Bethel to the West and Ai to the East. And there he built an altar to Yahweh and called on the name of Yahweh.'
Abram is surveying the land and finding places for his herds and flocks to feed. But wherever he goes he does not forget the public worship of God.
“Called on the name of Yahweh”. A technical term for Yahweh worship (see Genesis 4:26). Abram is announcing to his family tribe that Yahweh is now the God of the land. The writer's mention of the two great walled Canaanite cities (both well attested) is deliberate in order to emphasise Abram's claim even in the face of these walled cities. It is an act of faith. He does not doubt that God can deal with the walled cities.
It is not said that he ‘called on the name of Yahweh' at Shechem. That was more of a temporary altar, built because of the covenant confirmed there. That was a more personal act of worship. This one is more important and is recognised as the primary altar for worship by the tribe at this time.
To Abram there is only one God. He is Yahweh, the Creator of all things and Judge of all the earth (Genesis 18:25, compare Genesis 13:13 where Sodom's sins are said to be ‘against Yahweh'). He is confident that Yahweh can work His will wherever He wishes, even in mighty Egypt (Genesis 12:10-20). He rarely needs to deal with the question of the gods of others. When he meets Melchizedech king of Jerusalem he is ready to accept that El Elyon, ‘the Most High God', maker of heaven and earth, is the same as Yahweh, for that is what he knows Yahweh to be (Genesis 14:22). The same is true of El Shaddai, ‘God the Almighty' (Genesis 17:1) and El ‘Olam ‘the Everlasting God' (Genesis 21:33). For to him Yahweh is all. But this is because the descriptions fit Yahweh, not because he is prepared to equate Him with any god. He is not primarily a syncretist.
“Pitched his tent”. The use of tents is paralleled by the “seventeen kings who lived in tents”, mentioned in a later Assyrian inscription, and the first of whom is referred to at Ebla (3rd millennium BC). The Amorite tent dwellers of the earlier myth of Martu, and references in the Tale of Sinuhe (c.1950BC) also confirm the use of tents at this time.