Genesis 17:21

21 But my covenant I will establish with Isaac, whom Sarah will bear to you by this time next year.”

Read Genesis 17:21 Using Other Translations

But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.
But I will establish my covenant with Isaac, whom Sarah shall bear to you at this time next year."
But my covenant will be confirmed with Isaac, who will be born to you and Sarah about this time next year.”