When a woman breast-feeds a child who is not hers, that results in some Islamic rulings, and what becomes mahram (forbidden for marriage) through breastfeeding is that which becomes mahram through blood ties. In this hadith, ‘Uqbah ibn al-Harith (may Allah be pleased with him) tells us that he married the daughter of Abu Ihab ibn ‘Aziz, whose name was Ghaniyyah and her kunya was Umm Yahya. Then a woman who was a wet-nurse came to him and told him that she had breast-fed him and the woman whom he had married; in other words, the woman whom he had married was his foster sister, because she had breast-fed both of them. ‘Uqbah (may Allah be pleased with him) responded by saying: I do not know that you breast-fed me, giving the excuse that he knew nothing about that, or he denied that she had breast-fed him in the first place, as if he was accusing her of lying. ‘Uqbah also sent word to the family of Abu Ihab to ask them about that, and they said: We are not aware that she breast-fed our daughter. So they also denied that the woman who was making this claim had breast-fed the wife. In order to find out what he should do, ‘Uqbah rode from Makkah, because that was where he lived, and he went to the Messenger of Allah (blessings and peace of Allah be upon him) in Madinah, to ask him about the matter. The Prophet (blessings and peace of Allah be upon him) replied “How [could you do that] after what was said?” In other words, how could you be intimate with her when it was said that she is your foster sister? That is not appropriate for a man of dignity and piety. So he separated them, in order to avoid falling into a dubious matter, or because his marriage was invalid, because the wet-nurse had affirmed that she had breast-fed both of them, although ‘Uqbah denied it. So the Prophet (blessings and peace of Allah be upon him) accepted her word and ordered ‘Uqbah to separate from his wife, and she married someone else. This hadith indicates that we should avoid dubious matters. It also indicates that one who does not know about a matter cannot have any argument against the one who does know it. It also highlights the keenness of the Sahabah to seek knowledge, and their commitment to that which would bring them closer to Allah (may He be exalted)..