Ruling 2492. Eight conditions must be fulfilled for breastfeeding to cause someone to become maḥram:

1. a child must breastfeed the milk of a woman who is alive. Therefore, if a child breastfeeds some of the required amount of milk from the breasts of a dead woman, it is of no use [i.e. the child does not become maḥram];

2. The woman’s milk must be from a legitimate birth, even if [the conception of the child was] from intercourse that ensued from a mistake (waṭʾ al‑shubhah). Therefore, if, supposedly, a woman produces milk without giving birth, or the milk of a child that was born from fornication is given to another child, the latter does not become maḥram to anyone;

3. the child suckles the milk from the breasts of the woman. Therefore, if the milk is poured into the child’s mouth, it has no effect;

4. the milk must be pure and not be mixed with anything;

5. the amount of milk required for someone to become maḥram must all be related to one husband. Therefore, if a nursing mother is divorced and then marries another man and becomes pregnant by him, and until she gives birth the milk that she has from her first husband remains [in her body], and, for example, before giving birth she breastfeeds the child eight times with the milk that is related to the first husband, and after giving birth she breastfeeds the child seven times with the milk that is related to the second husband, then in such a case, the child does not become maḥram to anyone;

6. the child must not vomit the milk. If he does, it has no effect;

7. the child must be breastfed to the extent that his bones become firm by the milk, and the milk has made the flesh of his body grow. If it is not known whether the child has been breastfed to this extent or not, in the event that the child breastfeeds to his fill for one day and one night or fifteen times in accordance with the next ruling, it is sufficient. However, if it is known that the milk has not had an effect on making the bones firm and growing the flesh of the child’s body, even though the child breastfed for one day and one night or fifteen times, then obligatory precaution must be observed; i.e. in such a case, the child must not marry [those who would become maḥram to him by means of breastfeeding], nor must he look at them as maḥrams would;

8. the child has not completed two years of age. If he is breastfed after he completes two years, he does not become maḥram to anyone. In fact, if, for example, before he completes two years he is breastfed eight times and after that he is breastfed seven times, he does not become maḥram to anyone. However, in the event that more than two years pass from the time a woman gives birth and she still carries milk, then, if she breastfeeds a child, this child becomes maḥram to those who were mentioned above.

Ruling 2493. It is clear from the previous ruling that the amount of milk that causes someone to become maḥram is based on three possible criteria:

1. [based on the amount that is suckled if] it is to the extent that it can commonly be said to have caused the flesh to grow and the bones to become firm. The condition here is that [the flesh growing and bones becoming firm] is based on the milk, not on food that is fed with the milk. However, a small amount of food that does not have an effect is no problem. If the child breastfeeds from two women and [a particular] amount of the growth of flesh or firming of bones is based on the milk of one of them and [a particular] amount based on [the milk of] the other, then both of them will be the child’s nursing mothers. But if the growth of flesh or firming of bones [in general] is based on the milk of both of them together, then it does not result in the child becoming maḥram;

2. based on time. The condition here is that the child does not breastfeed from another woman or eat any food during the one day and night period. However, there is no problem if the child drinks water, takes some medicine, or eats some food to the extent that he cannot be said to have ‘eaten food within [the one day and night period]’. Furthermore, the child must have regularly drank milk during the day and night when he needed or wanted to and was not delayed in doing so. In fact, based on obligatory precaution, the start of the day and night period must be counted from the time the child was hungry, and the end of the period must be considered the time he became full;

3. based on number. The condition here is that the child must suckle the milk of one woman fifteen times, and between those times he must not suckle from another woman. However, there is no problem if he eats some food or an interval occurs in between those fifteen times. Furthermore, each time the child breastfeeds, he must do so fully, meaning that he must go from being hungry to becoming completely full without an interval. However, there is no problem if while the child suckles he takes new breaths or stops a little such that from the time he puts the nipple in his mouth to when he becomes full, it can be counted as one go.

Ruling 2494. If a woman breastfeeds a child from the milk that is related to her husband and later marries another man and then breastfeeds another child from the milk that is related to her second husband, the two children do not become maḥram to each other.

Ruling 2495. If a woman breastfeeds a number of children with the milk that is related to one husband, all of them become maḥram to one another as well as to the husband and the woman who breastfed them.

Ruling 2496. If a person has a number of wives and all of them breastfeed a child and fulfil the conditions mentioned previously, then all of the children become maḥram to one another as well as to the man and all the women.

Ruling 2497. If a person has two nursing mothers and, for example, one of them breastfeeds a child eight times and the other breastfeeds him seven times, the child does not become maḥram to anyone.

Ruling 2498. If a woman fully breastfeeds a boy and a girl from the milk that is related to one husband, then the brothers and sisters of the girl do not become maḥram to the brothers and sisters of the boy.

Ruling 2499. A man cannot marry women who have become his wife’s nieces through breastfeeding without his wife’s permission. Furthermore, if a man sodomises a boy who is not of the age of legal responsibility (bāligh), he cannot marry the boy’s nursing daughter, sister, mother, or grandmother, i.e. those who are his daughter, sister, mother, or grandmother through breastfeeding. The same applies, based on obligatory precaution, if the sodomiser is not bāligh or the sodomised individual is bāligh.

Ruling 2500. A woman who has breastfed a man’s brother does not become maḥram to that man.

Ruling 2501. A man cannot marry two sisters, even if they are nursing sisters, meaning that they are sisters to each other through breastfeeding. In the event that he marries two sisters and later realises that they are sisters, then, if the marriage contracts were concluded at the same time, both marriage contracts are void. However, if they were not concluded at the same time, the marriage contract of the first is valid (ṣaḥīḥ) and the marriage contract of the second is void.

Ruling 2502. If a woman breastfeeds any of the people listed below with the milk that is related to her husband, her husband does not become unlawful for the woman:

1. her brothers and sisters;

2. her paternal and maternal uncles and aunts and their offspring;

3. her grandchildren, although if she were to breastfeed her daughter’s child, it would cause her daughter to become unlawful for her own husband;[1]

4. her nephews and nieces;

5. her husband’s brothers and sisters;

6. her husband’s nephews and nieces;

7. her husband’s paternal and maternal uncles and aunts;

8. her husband’s grandchildren from his other wives.

Ruling 2503. If a woman breastfeeds the daughter of a man’s paternal or maternal aunt, she does not become maḥram to him.

Ruling 2504. If a man has two wives and one of them breastfeeds the child of the other wife’s paternal uncle, then the wife whose paternal uncle’s child breastfed the milk does not become unlawful for her husband.