there can be no woman whose hand is lawful to him while her body is unlawful, nor the reverse. This is why we previously stated that if he were to divorce one of her limbs, she would be divorced, because divorce cannot be divided.
His words, “to any part or the whole of a woman whom he is permanently forbidden to marry”: with regard to the woman to whom the comparison is made, there is no difference between the whole and a part. Thus, if he says, “You are to me like my mother’s hand,” ẓihār is valid, just as it is if he says, “You are to me like my mother’s back.” The back is part of the mother. Therefore, if he likens his wife, in whole or in part, to a woman who is forbidden to him, in whole or in part, ẓihār is valid, because ẓihār cannot be divided: it is inconceivable for a woman’s hand to be lawful to him while the rest of her body is unlawful. Since it cannot be divided, a part is equivalent to the whole.
His words, “whom he is permanently forbidden to marry,” indicate that the woman to whom the comparison is made must be one whom he is permanently forbidden to marry—that is, forbidden in perpetuity. This excludes a woman who is forbidden to him only temporarily, such as his wife’s sister. Thus, if he says to his wife, “You are unlawful to me like your sister’s back,” her sister is forbidden to him as long as he remains married to his wife; but if his wife were irrevocably separated from him, her sister would become lawful for him. This, then, does not constitute ẓihār.
His words, “to any part or the whole of a woman whom he is permanently forbidden to marry”: if he likens her to an unrelated woman to whom he is not married, saying, “You are to me like so-and-so,” he has not pronounced ẓihār, because she is not forbidden to him.
Likewise, if he likens her to his father’s back, saying, “You are to me like my father’s back,” this is not ẓihār, because the author says, “a woman whom he is forbidden to marry.”
Thus, if he likens her to any man, it is not ẓihār; if he likens her to an unrelated woman, it is not ẓihār; and if he likens her to a woman who is forbidden to him only temporarily, it is not ẓihār.