Abraham was a hundred years old: the standard birth report in Genesis states the age of the father at the time of the birth of the son. See the introduction to chapter 5. In some translations this information about Abraham’s age is placed at the beginning of verse 2: “When Abraham was a hundred years old, his wife Sarah became pregnant and bore him a son.” Alternatively verse 5 may be placed before verse 2 and not repeated.

When his son Isaac was born to him: that is, “when Isaac was born” or “when Abraham’s son Isaac was born.” Some languages place the time clause first.

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .