Genesis 17:22-27 NLT

22 That ended the conversation, and God left Abraham.
23 On that very day Abraham took his son Ishmael and every other male in his household and circumcised them, cutting off their foreskins, exactly as God had told him.
24 Abraham was ninety-nine years old at that time,
25 and Ishmael his son was thirteen.
26 Both were circumcised the same day,
27 along with all the other men and boys of the household, whether they were born there or bought as servants.