The angel of the LORD also said to her: this expression may need to be adjusted for stylistic reasons to something like “He also said” or “He also told her.” New International Version has “The angel added.”

I will so greatly multiply your descendants that they cannot be numbered for multitude: as the text stands, this promise comes before the promise of the birth of a son in verse 11. In 15.4-5 the promise of a son is given to Abram followed by the promise of numerous descendants. Descendants translates the Hebrew “seed.” This line may be rendered, for example, “I will increase your descendants until no one will be able to count them” or “I will cause you to have so many offspring that they cannot be counted.”

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 .