Abu Huraira reported God's Messenger as saying, “A man may not marry a woman and her paternal aunt, or a woman and her maternal aunt.” (Bukhari and Muslim.)

‘A’isha reported God’s Messenger as saying, “What is unlawful by reason of consanguinity is unlawful by reason of fosterage.” Bukhari transmitted it.

My paternal uncle through fosterage came and asked permission to enter, but I refused to allow him till I asked God’s Messenger. When he came I asked him and he said, “He is your paternal uncle, so give him permission.” I replied, “Messenger of God, it was only the woman who suckled me and not the man” whereupon he said, “He is your paternal uncle, so let him come in where you are.” That was after seclusion was instituted for us. (Bukhari and Muslim.)

‘Ali said, “Messenger of God, would you like the daughter of your paternal uncle Hamza, for she is the most beautiful girl in Quraish?” He replied, “Do you not know that Hamza is my foster-brother, and that God has prohibited by reason of fosterage what He has prohibited by reason of genealogy?” Muslim transmitted it.

Umm al-Fadl stated that God’s Prophet said, “Being suckled once or twice does not make marriage unlawful.” In ‘A’isha’s version he said, “One or two sucks do not make marriage unlawful.” In another by Umm al-Fadl he said, “One suckling or two does not make marriage unlawful.” These are versions by Muslim.

‘A’isha said that in what was sent down in the Qur’an ten known sucklings made marriage unlawful, but they were abrogated by five known ones, and when God’s Messenger died these words were among what was recited in the Qur’an. Muslim transmitted it.

She said that the Prophet visited her when a man was with her and he seemed to disapprove of that. She told him that he was her brother and he replied, “Consider* who your brothers are, for fosterage is that consequent on hunger” (Fosterage applies only to infants and not to children who are able to take solid food).* The verb is in the plural, indicating that this is a general instruction and not simply a reply to A’isha.(Bukhari and Muslim.)

‘Uqba b. al-Harith said he married a daughter of Ihab b. 'Aziz and a woman came and said she had suckled 'Uqba and the woman whom he had married, to which he replied, “I am not aware that you suckled me, and you did not inform me.” So he sent to the family of Abu Ihab and asked them, and when they told him that they did not know whether she had suckled their daughter he rode to the Prophet in Medina and asked him. God’s Messenger said, “How can you hesitate when you have been told?” ‘Uqba therefore separated from her and she married another husband. Bukhari transmitted it.

At the battle of Hunain God’s Messenger sent an army to Autas, and they met an enemy and fought with them. . Having prevailed over them and taken captives the Prophet’s companions seemed to hold back from having intercourse with them because of their husbands among the polytheists. Then God most high sent down regarding that, “And women already married, except those whom your right hands possess” (Al-Qur’an 4:24). That means that they were lawful for them when their ‘idda* period came to an end. * The period which a widow or divorced woman must observe before remarriage. See Ch. 26.Muslim transmitted it.

Abu Huraira said that God’s Messenger forbade that a woman should be married to one who had married her paternal aunt, or a paternal aunt to one who had married her brother’s daughter, or a woman to one who had married her maternal aunt, or a maternal aunt to one who had married her sister's daughter. A younger sister must not be married to one who has married an elder sister, nor an elder sister to one who has married a younger sister. Tirmidhi, Abu Dawud, Darimi and Nasa’i transmitted it, Nasa’i’s version ending with “her sister’s daughter.”

My maternal uncle Abu Burda b. Niyar passed me carrying a standard, and I asked him where he was going. He replied, “The Prophet has sent me to bring him the head of a man who has married his father’s wife.” A version by Abu Dawud, Nasa’i, Ibn Majah and Darimi has, “He has ordered me to cut off his head and take his property.” This version has “my paternal uncle” instead of “my maternal uncle.”Tirmidhi and Abu Dawud transmitted it.

Umm Salama reported God’s Messenger as saying, “The only suckling which makes marriage unlawful is that which is taken from, the breast and enters the bowels, and is taken before the time of weaning.” Tirmidhi transmitted it.

Hajjaj b. Hajjaj al-Aslami quoted his father as saying, “Messenger of God, what will remove from me the obligation due for fostering a child.”* He replied, “A slave or a slave-girl of good quality.” *It is said that Arabs liked to give a woman who had fostered a child something over and above the hire. This tradition deals with the amount to be considered full compensation for services rendered. Tirmidhi, Abu Dawud, Nasa’i and Darimi transmitted it.

When I was sitting with the Prophet a woman came forward and the Prophet spread out his cloak and she sat on it. Then when she went away someone said that this woman had suckled the Prophet. Abu Dawud transmitted it.

Ibn ‘Umar told that Ghailan b. Salama ath-Thaqafi accepted Islam and that he had had ten wives in the pre-Islamic period who accepted Islam along with him; so the Prophet told him to keep four and separate from the rest of them. Ahmad, Tirmidhi and Ibn Majah transmitted it.

When I accepted Islam I had five wives, so I consulted the Prophet and he said, “Separate from one and keep four.” I therefore decided on the one who had been longest with me and had been barren for sixty years,* and separated from her. * This statement may seem strange when one considers that Naufal is said to have died in the Caliphate of Yazid b. Mu'awiya (60-64 A.H.). Some say he lived 60 years in the pre-Islamic period and 60 years in Islam. Others says he died aged 100. He is said to have accepted Islam at the Conquest of Mecca. The tradition cannot mean that he had been married to this woman for 60 years; it probably indicates that she was both barren and much older than he. She was possibly his first wife. Cf. Ibn Abu Hatim, al-Jarh wat-ta’dil, IV, i, 487 i.; Isti'ab, p. 293 ; Ibn Hajar, Tahdhib, x, 492; Isaba, iii, 1191.It is transmitted in Sharh as-sunna.

Ad-Dahhak b. Fairuz ad-Dailamli told on his father’s authority that he had said, "Messenger of God, I have accepted Islam and I am married to two sisters." He replied, “Choose whichever of them you wish.” Tirmidhi, Abu Dawud and Ibn Majah transmitted it.

Ibn ‘Abbas told that a woman who had accepted Islam married, and her husband (i.e. the one she had left to marry another when she became a Muslim) went to the Prophet and said, "Messenger of God, I have accepted Islam and she knew that I had done so.” So God’s Messenger took her away from her second husband and restored her to her first. In a version he said, “She accepted Islam along with me,” so he restored her to him. Abu Dawud transmitted it.

In Sharh as-sunna it is related that the Prophet restored a number of women to their husbands by the first marriage when they had both accepted Islam after the change of religion and dwelling. Among them was the daughter of al-Walid b. Mughira, the wife of Safwan b. Umayya. She accepted Islam on the day of the Conquest, but her husband fled from Islam. Then his cousin Wahb b. ‘Umair was sent to him with God’s Messenger’s cloak as a guarantee of security to Safwan, and when he came God’s Messenger granted him a respite of four months before accepting Islam, so she stayed with him. Umm Hakim daughter of al-Harith b. Hisham, the wife of Ikrima b. Abu Jahl, accepted Islam in Mecca on the day of the Conquest, but her husband fled from Islam and went to the Yemen. Umm Hakim journeyed and came to him in the Yemen, and when she invited him to accept Islam he did so, and they remained married. Malik transmitted it in mursal form on the authority of Ibn Shihab.

Seven classes of women are prohibited by reason of consanguinity and seven by reason of relationship by marriage. He then recited, "Prohibited to you are your mothers ...” (Al-Qur’an 4:23).Bukhari transmitted it.