Romans 4:17-19

(as it is written [in Scripture], “I HAVE MADE YOU A FATHER OF MANY NATIONS”) in the sight of Him in whom he believed, that is, God who gives life to the dead and calls into being that which does not exist. [Gen 17:5] In hope against hope Abraham believed that he would become a father of many nations, as he had been promised [by God]: “SO [numberless] SHALL YOUR DESCENDANTS BE.” [Gen 15:5] Without becoming weak in faith he considered his own body, now as good as dead [for producing children] since he was about a hundred years old, and [he considered] the deadness of Sarah’s womb. [Gen 17:17; 18:11]