Genesis 21:4

21:4 When his son Isaac was eight days old, ¹  Abraham circumcised him just as God had commanded him to do. ² 

[21:4]  ¹ tn Heb “Isaac his son, the son of eight days.” The name “Isaac” is repeated in the translation for clarity.

[21:4]  ² 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).