NET
19 God said, “No, Sarah your wife is going to bear you a son, and you will name him Isaac. I will confirm my covenant with him as a perpetual covenant for his descendants after him.
Darby
19 And God said, Sarah thy wife shall indeed bear thee a son; and thou shalt call his name Isaac; and I will establish my covenant with him, for an everlasting covenant for his seed after him.
KJV
19 And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, [and] with his seed after him.