2483. The following are the eight conditions under which suckling child becomes the cause of being Mahram.
2484. It is necessary that the suckling child should not have taken
any other food, or sucked milk from any other person, during one full day and
night. However, it it takes very little food, so little that one may not say
that it has taken any food in between, there is no harm in it.
Also, it should have suckled the milk of only one woman fifteen times, and during
these fifteen times, it should not have sucked the milk of any other woman.
And it should have sucked milk every time without a gap, though, if while suckling
milk it pauses to breathe, or waits a little, in a manner that from the time
it started till the end, it is taken as one suckling, there is no objection.
2485. If a woman suckles a child from the milk of her husband, and when she later marries another man, suckles another child from the milk of her second husband, those two children do not become Mahram of each other, although it is better that they do not marry each other.
2486. If a woman suckles several children from the milk of one husband, all of them become Mahram of one another, as well as of the husband, and of the woman who suckled them.
2487. If a man has more than one wife, and every one of them suckles a child in accordance with the conditions mentioned above, all those children become Mahram of one another, as well as of that man, and of all those wives.
2488. If a man has two nursing wives, and if, for example, one of them suckles the child eight times and the other suckles it seven times, the child does not become Mahram of any one of them.
2489. If a woman gives full milk to a boy and a girl from the milk of one husband, the sisters and brothers of that girl will not become Mahram of the sisters and brothers of that boy.
2490. A man cannot marry without the permission of his wife, those women who became her nieces (sister's daughter or brother's daughter) owing to the suckling of milk. Also, if a person commits sodomy with a boy, he cannot marry his milk daughter, sister, mother and paternal grandmother by means of sucking milk. This rule applies also in the situation where an active partner in sodomy is not baligh, or when the passive partner is baligh.
2491. A woman who suckles the brother of a person, does not become Mahram of that person, although the recommended precaution is that he should not marry her.
2492. A man cannot marry two sisters even if they may be milk sisters, that is, they have become sisters by means of suckling milk. If he marries two women and understands later that they are sisters, if he married them at one and the same time, both the Nikah will be void. But if he did not marry them at one time, the first marriage will be valid, and the second will be void.
2493. If a woman suckles the following persons from her husband's milk, her husband does not become haraam for her, although it is better to observe precaution.
2494. If a woman suckles the paternal aunt's daughter, or maternal aunt's daughter of a man, she (the woman who suckles) does not become Mahram of that man. However, the recommended precaution is that he should refrain from marrying that woman.
2495. If a man has two wives, and one of them suckles the paternal uncle's son of the other wife, the wife who suckled does not become haraam for her husband.