The Successors of the Companions (Tabi`un) used to ask the Companions (may Allah be pleased with them) and learn the religion from them. The Companions (may Allah be pleased with them) were keen to transmit the religion to them, teach them, and issue Fatwas for them concerning the new matters that arose.In this Hadith, the Successor `Amr ibn Ash-Sharid (may Allah have mercy on him) narrated: "`Abdullah ibn `Abbas (may Allah be pleased with him) was asked whether, if a man had two female slaves, and one of them nursed a slave-boy, and the other had nursed a slave-girl." That is: one of the two slave women suckled a female child, and the other slave woman suckled a male child. Then he was asked: "Is it permissible for the boy to marry the girl?" That is: is it permissible for the boy who was suckled by the first slave woman to marry the girl who was suckled by the second? Ibn `Abbas (may Allah be pleased with him) said, “No,”—that is, it is not permissible for them to marry one another. “The origin of the milk is one,” meaning: both women were owned by the same man, and it was he who fathered both children. The milk by which the two infants were breastfed was produced as a result of a single man’s procreative act, and thus the children are considered milk-siblings..