Why does the Scripture say that Abraham sacrificed his "only-begotten son" (Heb. 11:17, Gen. 22:2) despite the fact that Isaac had a step-brother Ishmael who was 14 years older than Isaac and was in fact the first-born son of Abraham?
migrated from christianity.stackexchange.com Mar 13 '12 at 2:34
The text in Genesis does not say "only-begotten" but does say "only". The beginning of the verse is:
My literal translation:
The word translated "your only [one]" is יְחִידְךָ . The same root, yud-chet-dalet, also gives us "yichud", which is the state of being alone with one other person. I don't know how much that bears on this, but I found it interesting.
In this context I think this could mean "only" in the sense of "only son remaining" (Yishmael has been banished already). Proximity to "whom you love" could suggest that while Avraham had two sons, he loved one and not the other (by the time of this event), though that's just one interpretation and I'm about to contradict it.
The rabbis recorded a midrash about this, with the conversation going roughly like this
God: Take your son.
(Babylonian talmud, Sanhedrin 89b.)
It's a translation issue. A better translation would say his "only-begotten male heir". Ishmael had been sent away and was illegitimate, and so was not in line to inherit anything from Abraham after his death.