Conditions of suckling which causes to be Mahram

2483. The following are the eight conditions under which suckling child becomes the cause of being Mahram.

That the child sucks the milk of a woman who is alive. It is of no consequence if milk is drawn from the breast of a woman who is dead.

That the milk of the woman should not be the product of fornication or adultery. Hence, if the milk for an illegitimate child is breastfed to another child, the latter will not become Mahram of anyone.

That the child sucks milk directly from the breasts of the woman. Hence, if milk is poured into its mouth, it has no consequence.

That the milk be pure and unadulterated.

That the milk be of one husband only. Hence, if a breast-feeding woman is divorced and then she marries another man by whom she becomes pregnant, if the milk of the first pregnancy still continues from the breast till she gives birth to the other child, and she feeds any child eight times with the milk from her first pregnancy before giving birth, and feeds the same child seven times with the milk from the second pregnancy, after giving birth, that child will not become Mahram of anyone.

That the child does not throw up the milk due to illness. If it vomits the milk, the suckling has no effect.

The suckling should be of such quantity that it could be said that the bones of the child were strengthened and the flesh allowed to grow. And if that cannot be ascertained, then if a child suckles for one full day and night, or if it suckles fifteen times to its fill, as will be explained later, it will be sufficient.
But if it is known that in spite of the child having suckled for one full day and night, or for fifteen times, the milk has not had any effect on the bones and the growth of flesh of the child, then one should not ignore exercising the precaution.

That the child should not have completed two years of his age, and, if it is suckled after it has completed two years of its age, it does not become Mahram of anyone. In fact, if, for example, it sucks milk eight times before completing its two years, and seven times after completing its two years, it does not become Mahram of anyone.
But, if milk continues from the breast for more than two years since a woman gave birth to her child, and she suckles the child continuously, that child will become Mahram of those who have been mentioned above.

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.

Her own brother and sister.

Her own paternal uncle and paternal aunt, and maternal uncle and maternal aunt.

The descendants of her paternal uncle and her maternal uncle.

Her nephew (brother's son).

Brother or sister of her husband.

Children of her sister, or children of her husband's sister.

Paternal uncle and paternal aunt and maternal uncle and maternal aunt of her husband.

Grand children of another wife of her husband.

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.