In this passage Isaac, Jacob, and Joseph are added to this group of the faithful which the writer of Hebrews calls a great cloud of witnesses (12:1). Isaac, Jacob and Joseph were men of faith (Hebrews 11:20-22). At the start of this chapter we are told that faith is the substance of things hoped for, the evidence of things not seen (11:1). What is not seen but yet believed by these men was what God had promised them and their descendants in the Abrahamic covenant. We often refer to what was promised to Abraham in terms of land, seed and blessing (Gen.12:1-3).
Isaac, in his blessing of Jacob seems to emphasize the blessing aspect of the Abrahamic Covenant, that is the relationship of blessing Israel would enjoy with the LORD. What God promised Abraham in Genesis 12:3, “I will bless those who bless you and curse those who curse you,” Isaac repeats in his blessing of Jacob (Gen.27:27-29)
Jacob emphasizes the seed or God’s promise of descendants when he blesses Joseph’s sons, Manasseh and Ephraim (Gen.48:15-16). “Let them grow into a multitude in the midst of the earth.”
Joseph, when he asks the children of Israel to bring his bones back to Canaan from Egypt emphasizes the promise of the land (Gen. 50:22-26). “I am dying; but God will surely visit you, and bring you out of this land to the land of which He swore to Abraham, to Isaac, and to Jacob.”
These men are examples of the faith we must have in God and His promises. It is a faith that helps us endure various trials and difficulties until we see what is presently unseen and possess what we now only hope for.