Is it permissible to marry an adopted person, and does that affect the lineage of the children?

If a young man possesses good character and religious devotion, Islamic law encourages accepting him as a husband, based on the Prophet Muhammad's (peace be upon him) saying: "If someone whose character and religious devotion you approve of comes to you [seeking marriage], then marry him [to your daughter]. If you do not do so, there will be tribulation on earth and widespread corruption."

The mere fact that a person is adopted does not legally prevent marriage to him, because adoption is forbidden and invalid, and the effects of filiation, including the prohibition of marriage due to affinity, do not apply to it. This is based on Allah's saying: "And He has not made your adopted sons your [real] sons." If his lineage is unknown, the possibility of commingling lineages is disregarded, so that the interest in marriage is not hindered. This is similar to the issue of a man's sister mixing with an uncounted number of women in a town, where he is permitted to marry from them due to the overriding interest.