What did god promsie Abraham in his convent?

The Abrahamic Covenant is an unconditional covenant. God made promises to Abraham that required nothing of Abraham. Genesis 15:18-21 describes a part of the Abrahamic Covenant, specifically dealing with the dimensions of the land God promised to Abraham and his descendants.

The actual Abrahamic Covenant is found in Genesis 12:1-3. The ceremony recorded in Genesis 15 indicates the unconditional nature of the covenant. The only time that both parties of a covenant would pass between the pieces of animals was when the fulfillment of the covenant was dependent upon both parties keeping commitments.

Concerning the significance of God alone moving between the halves of the animals, it is to be noted that it is a smoking furnace and a flaming torch, representing God, not Abraham, which passed between the pieces. Such an act, it would seem, should be shared by both parties, but in this case it is doubtless to be explained by the fact that the covenant is principally a promise by God. He is the one who binds Himself.

God caused a sleep to fall upon Abraham so that he would not be able to pass between the two halves of the animals. Fulfillment of the covenant fell to God alone. God determined to call out a special people for Himself through whom He would bring blessing to all the nations.

The Abrahamic Covenant is paramount to a proper understanding of the kingdom concept and is foundational to Old Testament theology. (1) The Abrahamic Covenant is described in Genesis 12:1–3 and is an unconditional covenant. There are no conditions attached to it (no “if” clauses, suggesting its fulfillment is dependent on man).

(2) It is also a literal covenant in which the promises should be understood literally.