It would appear that those who permit a man to have nine wives have relied on what they call the “aggregating” interpretation of the verse just mentioned—namely, adding together the numbers in the Almighty’s words, “two at a time, three, or four” (al-Nisāʾ 4:3).
Section Six: The Impediment of Combining
The scholars are unanimous that two sisters may not be joined together in a single marriage contract, because of His statement, “and that you should combine two sisters [in marriage]” (al-Nisāʾ 4:23). They differed, however, about possessing both sisters simultaneously through right-hand ownership. Most jurists prohibit it, while a minority allow it.
The root of their disagreement lies in the interplay between two general propositions. On the one hand stands the comprehensive wording, “and that you should combine two sisters,” and on the other the equally general exception at the close of the verse: “except those whom your right hands possess” (al-Nisāʾ 4:24). The exception could be read as referring only to the clause immediately before it, or as applying to every prohibition listed in the verse—apart from the cases on which consensus has ruled it irrelevant. If the latter reading is adopted, ownership by right hand would be exempted from the ban on combining sisters; if the former, the prohibition remains absolute, all the more so if one grounds it in the inherent bond of sisterhood or in some other rationale shared by the two women.
Among those who forbid combining sisters through ownership, a further dispute arose when one of them is a lawful wife and the other a slave-woman. Mālik and Abū Ḥanīfah disallowed the combination, whereas al-Shāfiʿī permitted it.
To the best of my knowledge the jurists also agree that it is unlawful to unite a woman with her paternal aunt or with her maternal aunt. This rests on the ḥadīth of Abū Hurayrah and on multiple-chain reports in which the Prophet—peace and blessings be upon him—declared: “A woman is not to be combined with her maternal aunt.”
They likewise concur that, in this context, “paternal aunt” refers to every woman who is the sister of a male ancestor of yours, whether that ancestor is direct or comes through another male, while “maternal aunt” refers to every woman who is the sister of a female ancestor of yours, whether direct or through another female—that is, the kinswomen on the mother’s side.
The jurists then disagreed: is this wording specific and intended to stay specific, or specific in form yet meant to convey a general rule? Those who held the latter view differed again over what general rule is intended.
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The majority of the jurists in the major centers say the wording is specific and meant to remain so; the prohibition extends no further than the relatives explicitly named.
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A second group say the text is specific in form but intends a general principle—namely, that one may not combine any two women who share a blood tie, whether that tie itself would make marriage between them unlawful or not. According to this view it is impermissible to unite, for example, two paternal cousins, two maternal cousins, a woman and her father’s cousin, or a woman and her mother’s cousin.
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A third group maintain that the prohibition covers only those pairs of women whose mutual kinship is such that, were one of them male and the other female, marriage between them would be forbidden. Some members of this group go further and require that this condition be met from both directions—that is, if each of the two