The incest story of Lot and his daughters has been borrowed from Zoroastrian traditions of the incest performed between Jam and Jamag, who were brother and sister. Jamag took advantage of the intoxicated state of her brother and had sex with him. What’s your response?

My response is that this is so obviously a false charge that the one making it ought to be embarrassed for even making this proposal.  I assume it is not you who came up with this, but found it at a Muslim website.   There are at least three reasons I reject this proposal:

First of all, the story of Lot and his daughters is from around 1900 BC, and was almost certainly part of the Book of Genesis by well before 1000 BC.  (Genesis probably took its final form after 1000 BC, but it existed in an earlier form well before this date) Therefore, the Genesis account precedes the story of Jam and Jamag by several centuries.  The myth of Jam and Jamag comes from the Avesta, which scholars propose was produced somewhere around 500 BC and not written down until the early centuries AD.  There is no way for this story to have moved from the Avesta to the Hebrew Bible.  Full stop.

Second of all, the story of Jam and Jamag is truly an obscure one.  I found it very difficult to even learn anything at all about it, despite research efforts.  My guess (and to be honest it is a guess) is that if you were to ask a Zoroastrian about Jam and Jamag, they would never have heard of this story at all.    It is fantastically unlikely that such a famous and long-established account in Genesis would be “borrowed” from an extremely obscure Zoroastrian tradition.  If anything, perhaps the second story is borrowed from the biblical story (but this is very unlikely for the third reason).

The third reason is that there is really virtually no parallel between the two stories.  I was able to find the story.  Here it is:    ThePahlavi Rivāyatgoes on to tell the story of how, one time Jam and thedēwwere on a drinking spree, Jamag switched clothes with theparīgand took her drunken brother to bed, thus performingxwēdōdah(next-of-kin marriage), by the virtue of which the two demons fell back into Hell. TheBundahišnalso reports that Jam and Jamag had twins, a man named Āspī(g)ān and a woman named *Zrēšom, who married and so continued the lineage (Bdh. 35.4). The story is reminiscent of the story of Lot and his daughters, who have intercourse with him when he is drunk, in order to continue the family (Genesis19:31-38).