The initial clause for God’s promise was made in these words may be restructured as “for this is what God said when he made the promise to Abraham.”

The scripture quotation in this verse represents a rather free combination of Genesis 18.10 and 14. At the right time (New English Bible “at the time fixed”; Jerusalem Bible “at such and such a time”; New American Bible “at this time”) is shown clearly by the passage in Genesis to mean “at this time next year” (An American Translation*).

Sarah will have a son may be rendered simply as “Sarah will possess a son” or it may be translated as “Sarah will give birth to a son” or “Sarah will have given birth to a son.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .