Genesis 17:23 WBT

²¹  But my covenant will I establish with Isaac, whom Sarah shall bear to thee at this set time in the next year.

²²  And he ceased talking with him, and God went up from Abraham.

²³  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 same day, as God had said to him.

²⁴  And Abraham [was] ninety and nine years old, when he was circumcised in the flesh of his foreskin.

²⁵  And Ishmael his son [was] thirteen years old, when he was circumcised in the flesh of his foreskin.