Mwanzo 17:19

Ndipo Mungu akasema, “Ndiyo, lakini mkeo Sara atakuzalia wewe mwana, nawe utamwita jina lake Isaki. Nitalithibitisha Agano langu naye kama Agano la milele kwa ajili yake na wazao wake baada yake.

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.