Genesis 21:4

21:4 When his son Isaac was eight days old, Abraham circumcised him just as God had commanded him to do.

tn Heb “Isaac his son, the son of eight days.” The name “Isaac” is repeated in the translation for clarity.

sn Just as God had commanded him to do. With the birth of the promised child, Abraham obeyed the Lord by both naming (Gen 17:19) and circumcising Isaac (17:12).