What is this you have done to us? is now a rhetorical question to which Isaac does not respond. Abimelech is probably referring to a punishment the local gods could inflict upon the people of Gerar. Revised English Bible translates “Why have you treated us like this?” We may also translate, for example, “Don’t you realize what you have done to us?” If the question must be expressed as a negative, we may say, for example, “You should never have done such a thing to us.” Us refers to Abimelech and the people of Gerar, which requires in some languages an exclusive pronoun form.

One of the people might … wife: unlike the case of Abraham and Pharaoh in 12.15, or Abimelech in 20.2, here Abimelech has not taken Rebekah into his harem. One of the people means one of the men of Gerar, somebody in Gerar. Lain translates a verb meaning to lie down. It is used in 19.33 and 35, where Lot’s daughters slept with their father to become pregnant. See discussion there. New English Bible says “might have gone to bed with.” Translators should use an expression that is suitable for public reading, but which at the same time will be clearly understood to refer to sexual intercourse.

You would have brought guilt upon us: Abimelech’s moral attitude is similar to that of Pharaoh in 12.10-20 and Abimelech in chapter 20. The thought is that, if somebody had slept with Rebekah, it would have caused the people of Gerar to be guilty of wrongdoing. To Abimelech this would have probably meant that the local gods would have punished all the people for the guilt of the offender. Guilt translates a noun meaning “offense,” “fault,” “sin.” If such a thing had happened, Isaac would have been, as Good News Translation says, “responsible for our guilt.” We may also say, for example, “You would have caused us to become guilty of wrong.” In some languages this idea is expressed as “It would be your fault that we carry the load of filthiness on our heads.” See comment on us at the beginning of this verse.

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 .