Is it permissible to nurse a baby boy and a baby girl from different mothers so that they become siblings through rada'a (nursing) for the purpose of forging a bond between the two families, given the parents' apprehension about the potential impact of this on their future marriage, and is this act forbidden or discouraged, especially since there is a history of consanguineous marriages that have caused hereditary diseases?

Breastfeeding a child with milk from a woman other than his mother is permissible in Islamic law, whether there is a need for it or not, based on the Almighty’s saying: "{And if you wish to have your children wet-nursed, there is no blame upon you}." This is done by employing a foreign wet nurse. Attention must be paid to accurately documenting the suckling child and the wet nurse to avoid marriage between mahrams due to fosterage, while also ensuring that the wet nurse possesses good qualities. As for the brotherhood of Islam, it is established among all Muslims. If the intention is to strengthen kinship through fosterage, then the parents must be obeyed if they prohibit this fostering, especially if the prohibition is out of fear of marriage being forbidden due to fosterage, and if the matter is easy and there is no harm to the child.