Sayyidah Umm al-Tufayl (may Allah be pleased with her) narrates that Sayyiduna Umar bin al-Khattab and Sayyiduna Ubayy bin Ka'b (may Allah be pleased with them both) differed about a pregnant woman whose husband dies and who then gives birth. Umm al-Tufayl said to Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him): Will you not tell Sayyiduna Umar (may Allah be pleased with him) the saying of the Messenger of Allah (peace and blessings be upon him) which he (peace and blessings be upon him) said to Sayyidah Subay'ah bint al-Harith (may Allah be pleased with her) when she gave birth a few days after her husband's death? Then the Messenger of Allah (peace and blessings be upon him) married her to a man.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21809