What is the opinion of Islam on giving the milk of a particular mother to a particular infant other than her own for the entire nursing period? If the answer is affirmative, what are the criteria which will guarantee the prevention of lineage confusion?

There is no legal impediment to this, since scholars have unanimously agreed on the permissibility of benefitting from human milk which is considered separate from the body due to the Qur`anic verse: “But if you are in discord, then there may breastfeed for the father another woman” [Al-Talaq: 6]. It must be noted that Islamic legal texts state that the prohibition established by milk-relations is tantamount to that established by blood relations when breastfeeding is completed within the prescribed period which is two lunar years from the time of birth. Consequently, breastfeeding makes a woman a mother- through-nursing to the child she suckles and all her children—those whom she nursed with, before or after it—stand in a sibling relationship to it. The criteria for avoiding lineage confusion are that a woman who breastfeeds a child who is not her own must remember and record the names of the children she breastfed as a precautionary measure as well as testify to this if she is called upon to do so. The aim is to order to avoid an unlawful marriage which may occur between the infants she nursed.