Genesis 18:2-15

2And he lifted up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground, 3And said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant: 4Let a little water, I pray you, be brought, and wash your feet, and rest yourselves under the tree: 5And I will bring a morsel of bread, and comfort ye your hearts; after that you shall pass on: for therefore are ye come to your servant. And they said, So do, as thou hast said.12 6And Abraham hastened into the tent to Sarah, and said, Make ready quickly three measures of fine meal, knead it, and make cakes upon the hearth.3 7And Abraham ran to the herd, and brought a calf tender and good, and gave it to a young man; and he hasted to dress it. 8And he took butter, and milk, and the calf which he had dressed, and set it before them; and he stood by them under the tree, and they ate.

9And they said to him, Where is Sarah thy wife? And he said, Behold, in the tent. 10And he said, I will certainly return to thee according to the time of life; and, lo, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him. 11Now Abraham and Sarah were old and well advanced in years; and it ceased to be with Sarah after the manner of women. 12Therefore Sarah laughed within herself, saying, After I am become old shall I have pleasure, my lord being old also? 13And the LORD said to Abraham, Why did Sarah laugh, saying, Shall I certainly bear a child, who am old? 14Is any thing too hard for the LORD? At the time appointed I will return to thee, according to the time of life, and Sarah shall have a son. 15Then Sarah denied, saying, I laughed not; for she was afraid. And he said, Nay; but thou didst laugh.