What is the ruling when both a man and a woman claim a child belongs to them?

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If a man and a woman both claim a lineage, there is no contradiction between their claims. The child is established as their offspring solely upon their mutual claim, just as if each had claimed him individually. This is permissible because it is possible the child resulted from a previous marriage or from sexual intercourse based on a misconception (watu' shubhah) between them.