Genesis 12:7

And the Lord appeared The first mention of a Theophany in the patriarchal narrative. What form it took, and in what way it was connected with the "sacred tree" or the altar, is not related.

Unto thy seed will I give this land The continuance of the Divine promise. In Genesis 12:2 we had the blessing of the people and the patriarch, in general terms. In this verse, immediately after the mention of the Canaanite occupation, possession of "this land" is promised to the descendants of Abram. This verse lays the foundation of the imperishable devotion of "the seed of Abram" to the Land of Promise.

builded he an altar Cf. Genesis 8:20. The building of an altar which implies the rite of sacrifice is mentioned in connexion with the promises and appearances of God, cf. 8, Genesis 13:18; Genesis 33:20; Genesis 35:1; Genesis 35:7.

Sacrifice was the expression of the patriarch's dependence on, communion with, and devotion to, Jehovah.