God also said to Abraham, "You must keep My covenant--you and your descendants in the generations after you.

Genesis 17:23
On that very day Abraham took his son Ishmael and all those born in his household or purchased with his money--every male among the members of Abraham's household--and he circumcised them, just as God had told him.

Genesis 18:19
For I have chosen him, so that he will command his children and his household after him to keep the way of the LORD by doing what is right and just, in order that the LORD may bring upon Abraham what He has promised."

Exodus 19:5
Now if you will indeed obey My voice and keep My covenant, you will be My treasured possession out of all the nations--for the whole earth is Mine.

And God said to Abraham, You shall keep my covenant therefore, you, and your seed after you in their generations.