Genesis Chapter 18 Verse 4Let a little water, I pray you, be fetched, and wash your feet, and rest yourselves under the tree:

But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.

And he left off talking with him, and God went up from Abraham.

And Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham's house; and circumcised the flesh of their foreskin in the selfsame day, as God had said unto him.

And Abraham [was] ninety years old and nine, when he was circumcised in the flesh of his foreskin.

And Ishmael his son [was] thirteen years old, when he was circumcised in the flesh of his foreskin.

In the selfsame day was Abraham circumcised, and Ishmael his son.

And all the men of his house, born in the house, and bought with money of the stranger, were circumcised with him.

And the LORD appeared unto him in the plains of Mamre: and he sat in the tent door in the heat of the day;

And he lift 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,

And said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant:

And I will fetch a morsel of bread, and comfort ye your hearts; after that ye shall pass on: for therefore are ye come to your servant. And they said, So do, as thou hast said.

And Abraham hastened into the tent unto Sarah, and said, Make ready quickly three measures of fine meal, knead [it], and make cakes upon the hearth.

And Abraham ran unto the herd, and fetcht a calf tender and good, and gave [it] unto a young man; and he hasted to dress it.

And 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 did eat.

And they said unto him, Where [is] Sarah thy wife? And he said, Behold, in the tent.

And he said, I will certainly return unto 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.

Now Abraham and Sarah [were] old [and] well stricken in age; [and] it ceased to be with Sarah after the manner of women.

Therefore Sarah laughed within herself, saying, After I am waxed old shall I have pleasure, my lord being old also?

And the LORD said unto Abraham, Wherefore did Sarah laugh, saying, Shall I of a surety bear a child, which am old?

Is any thing too hard for the LORD? At the time appointed I will return unto thee, according to the time of life, and Sarah shall have a son.

The Book of Genesis, Chapter 18, Verse 4