Muwatta Imam Malik (Riwayat Yahya)

It is narrated from Abdullah bin Abi Umayyah that a woman's husband died, so she observed the waiting period ('iddah) for four months and ten days, then married another man. She had been with him for four and a half months when she gave birth to a fully developed boy. Her husband came to Sayyiduna Umar, may Allah be pleased with him, and described the situation. Sayyiduna Umar, may Allah be pleased with him, summoned some old women who had lived during the time of ignorance and asked them about it. One of the women said: I will tell you about this woman. She became pregnant from her first husband who died, and the menstrual blood dried up the child in her womb. When she married again, the semen of the new husband reached her, which caused the child to move and grow. Sayyiduna Umar, may Allah be pleased with him, confirmed this and annulled the marriage, saying: It is good that nothing bad has reached me about you. The lineage of the boy was established from the first husband.