Idan Dershowitz said that he had studied the development of the Old Testament and found that the original version of Leviticus expressly permitted gay sex.
Writing in the New York Times, he explained: "Chapter 18 of Leviticus contains a list of forbidden incestuous acts, followed by prohibitions against sex with a menstruating woman, bestiality and various other sexual acts.
"In Verse 22, we find its most famous injunction 'You shall not lie with a male as with a woman; it is an abomination'.
"Leviticus 20:13 repeats this law, along with a punishment for those who violate it: 'They shall be put to death; their blood is upon them'."
He went on to write: "Like many ancient texts, Leviticus was created gradually over a long period and includes the words of more than one writer. Many scholars believe that the section in which Leviticus 18 appears was added by a comparatively late editor, perhaps one who worked more than a century after the oldest material in the book was composed.
"An earlier edition of Leviticus, then, may have been silent on the matter of sex between men."
"As I argue in an article published in the latest issue of the journal Hebrew Bible and Ancient Israel, there is good evidence that an earlier version of the laws in Leviticus 18 permitted sex between men. In addition to having the prohibition against same-sex relations added to it, the earlier text, I believe, was revised in an attempt to obscure any implication that same-sex relations had once been permissible."
Concluding his opinion piece, he said: "One can only imagine how different the history of civilization might have been had the earlier version of Leviticus 18's laws entered the biblical canon."
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