At Isaac generation no new items are added to Abraham's Covenant. It is, though confirmed as having passed to him.

Confirmed to Isaac

God did not stop at Abraham. The next generation was told the same thing. This time, though, since the covenant was set, there was no need to execute a new covenant. All that remained was reassurance for the people involved that God had a great thing planned.

We see this in Isaac's life in Genesis chapter 26. The following is the relevant text:

1Now there was a famine in the land -- besides the earlier famine of Abraham's time -- and Isaac went to Abimelech king of the Philistines in Gerar. 2The LORD appeared to Isaac and said, "Do not go down to Egypt; live in the land where I tell you to live. 3Stay in this land for a while, and I will be with you and will bless you. For to you and your descendants I will give all these lands and will confirm the oath I swore to your father Abraham. 4I will make your descendants as numerous as the stars in the sky and will give them all these lands, and through your offspring all nations on earth will be blessed, 5because Abraham obeyed me and kept my requirements, my commands, my decrees and my laws." 6So Isaac stayed in Gerar. Genesis 26:1-6 (Genesis 26:1-6 NIV)

Each of the main components of Abraham's covenant are repeated here again. Isaac will now be blessed.(Gen 26:3) Isaac, together with his dependents will receive the land.(Gen 26:3) Isaac will have numerous offspring, as numerous as the stars in the sky.(Gen 26:4) Finally, through his offspring, all nations on earth will be blessed.(Gen 26:4)

The nature of the covenant being made with Abraham, not with Isaac, is reiterated.(Gen 26:5) Isaac is not required to do anything. Because of the covenant that God made with Abraham it is sure to happen. It will happen as surely as God exists. This has less requirement placed on Isaac than even the New Covenant. Isaac does not even need to believe that this will happen, it still will. Those of us, under the New Covenant, are required to believe.

The next generation, Jacob, has the same thing happen. We now turn there.