'Father Of Many Nations' in the Bible

just as it is written [Gen. 17:5], "I [i.e., God] have made you [i.e., Abraham] forefather of many nations." He received this promise in the presence of God, in whom he believed, and who gives life [back] to dead people and who refers to things [promised] as though they were [already] fulfilled.

Abraham hoped for what he believed [God had promised], even when there seemed little hope [of it happening], so this made him forefather of many nations, according to the words spoken to him [Gen. 15:5], "Your descendants will be many."