Muslims and Jews have a long history of cousin marriage.
CONSANGUINITY AMONG JEWS - JewishEncyclopedia.com
Complete contents the 1906 Jewish Encyclopedia.
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By: Cyrus Adler, Joseph Jacobs. Owing to their dispersion among populations professing creed different from their own, Jews have married near relatives more frequently than the rest of the world. The marriage of first cousins and even of uncle and niece is quite legal and usual among them ( see Marriage ). The limitations on the marriage of those of priestly descent would tend to limit the choice of Cohens to …