What is the ruling on some women being lenient in the matter of breastfeeding their sons or daughters, under the pretext of the mother's desire for her son to have a brother through breastfeeding, while there is no urgent need for breastfeeding? And is that considered tampering and mixing of lineages?

There is no harm in seeking a wet nurse, and it entails many benefits. The purpose of breastfeeding is not merely to satisfy hunger; rather, it has an effect on the transfer of some characteristics to the nursling. Therefore, seeking a noble woman as a wet nurse is a cause for the child's nobility. It is disliked to be nursed by the milk of the immoral, polytheistic women, and the foolish, as mentioned by Ibn Qudamah and Ibn Nujaim. Among the wisdoms of breastfeeding is the expansion of social circles and the provision of a mahram (unmarriageable kin) for a woman who has no child or no brother.

Some scholars have prohibited breastfeeding without a reason, fearing that such an act would not be properly documented, potentially leading to a man marrying his suckling sister. It is obligatory upon women not to breastfeed every child unnecessarily. If they do breastfeed, they should record it, publicize it, and write it down as a precaution.