FOSTERAGE Arabic raza’ah, riza’ah رضاعة
According to Abu Hanifah, the period of fosterage is thirty months but the two disciples, Yusuf and Muhammad, hold it to be two years, whilst Zufar maintains that it is three years. Fosterage with respect to the prohibitions attached to it is of two kinds: first, where a woman takes a strange child to nurse, by which all future matrimonial connection between that child and the woman, or her relations within the prohibited decrees, is rendered illegal; secondly, where a woman nurses two children, male and female, upon the same milk, which prohibits any future matrimonial connection between them. For further particulars on this subject, see Hamilton’s Hidayah, vol I, page 187.

Based on Hughes, Dictionary of Islam