The Son of the Promise

(18: 1 – 21: 34)

So at the beginning of ch. 18 (1-15), the Lord himself with two attendant angels visits Abraham as he sits at his tent door, and despite Sarah's incredulous laughter, which echoes Abraham’s own (17: 17), the aged couple are told of the impending birth of Isaac. Against all the normal rules of nature, and despite man's good intentions, God chooses his own way in his own time to further the divine plan. "Is anything too hard for the Lord?" (18:14).

The story in ch. 20 which is the E (Elohist) version of 12: 10-20 and repeats its motif, stressing the divine determination that nothing must stand in the way of the promise, is followed in 21:1-8 at last with the birth of a natural son to Abraham and Sarah. The suspense and protracted delay have been intentional. When human hope is at the point of exhaustion God shows his hand. The son of the promise is born and is named Isaac, "laughter", a reference to the incredulous reaction of his aged father and mother (17: 17; 18: 12), but also to the joyous welcome which his birth occasioned (21: 6).