Genesis 17:15-Genesis 18:21 - Isaac's Birth Promised
15 And God said, As for Sarai, your wife, from now her name will be not Sarai, but Sarah. 16 And I will give her a blessing so that you will have a son by her: truly my blessing will be on her, and she will be the mother of nations: kings of peoples will be her offspring.
17 Then Abraham went down on his face, and laughing, said in his heart, May a man a hundred years old have a child? will Sarah, at ninety years old, give birth? 18 And Abraham said to God, If only Ishmael's life might be your care!
19 And God said, Not so; but Sarah, your wife, will have a son, and you will give him the name Isaac, and I will make my agreement with him for ever and with his seed after him. 20 As for Ishmael, I have given ear to your prayer: truly I have given him my blessing and I will make him fertile and give him great increase; he will be the father of twelve chiefs, and I will make him a great nation. 21 But my agreement will be with Isaac, to whom Sarah will give birth a year from this time. 22 And having said these words, God went up from Abraham.
23 And Abraham took Ishmael, his son, and all whose birth had taken place in his house, and all his servants whom he had made his for a price, every male of his house, and on that very day he gave them circumcision in the flesh of their private parts as God had said to him. 24 Abraham was ninety-nine years old when he underwent circumcision. 25 And Ishmael, his son, was thirteen years old when he underwent circumcision. 26 Abraham and Ishmael, his son, underwent circumcision on that very day. 27 And all the men of his house, those whose birth had taken place in the house and those whom he had got for money from men of other lands, underwent circumcision with him.
1 Now the Lord came to him by the holy tree of Mamre, when he was seated in the doorway of his tent in the middle of the day; 2 And lifting up his eyes, he saw three men before him; and seeing them, he went quickly to them from the door of the tent, and went down on his face to the earth; 3 And said, My Lord, if now I have grace in your eyes, do not go away from your servant: 4 Let me get water for washing your feet, and take your rest under the tree: 5 And let me get a bit of bread to keep up your strength, and after that you may go on your way: for this is why you have come to your servant. And they said, Let it be so.
6 Then Abraham went quickly into the tent, and said to Sarah, Get three measures of meal straight away and make cakes. 7 And running to the herd, he took a young ox, soft and fat, and gave it to the servant and he quickly made it ready; 8 And he took butter and milk and the young ox which he had made ready and put it before them, waiting by them under the tree while they took food.
9 And they said to him, Where is Sarah your wife? And he said, She is in the tent.
10 And he said, I will certainly come back to you in the spring, and Sarah your wife will have a son. And his words came to the ears of Sarah who was at the back of the tent-door.
11 Now Abraham and Sarah were very old, and Sarah was past the time for giving birth. 12 And Sarah, laughing to herself, said, Now that I am used up am I still to have pleasure, my husband himself being old?
13 And the Lord said, Why was Sarah laughing and saying, Is it possible for me, being old, to give birth to a child? 14 Is there any wonder which the Lord is not able to do? At the time I said, in the spring, I will come back to you, and Sarah will have a child.
15 Then Sarah said, I was not laughing; for she was full of fear. And he said, No, but you were laughing.
16 And the men went on from there in the direction of Sodom; and Abraham went with them on their way. 17 And the Lord said, Am I to keep back from Abraham the knowledge of what I do; 18 Seeing that Abraham will certainly become a great and strong nation, and his name will be used by all the nations of the earth as a blessing? 19 For I have made him mine so that he may give orders to his children and those of his line after him, to keep the ways of the Lord, to do what is good and right: so that the Lord may do to Abraham as he has said. 20 And the Lord said, Because the outcry against Sodom and Gomorrah is very great, and their sin is very evil, 21 I will go down now, and see if their acts are as bad as they seem from the outcry which has come to me; and if they are not, I will see.