Musnad Ahmad 1279:0

Narrated to us by Abd al-Razzaq, who said: Narrated to us by Ma'mar, from Ayyub, from Ibn Abi Mulaykah, from al-Miswar ibn Makhramah, that Subay'ah al-Aslamiyyah was married to Sa'd ibn Khawlah, and he was one of those who witnessed Badr. He died during the Farewell Pilgrimage while she was pregnant. She did not wait long after his death before she gave birth. When she had finished her period of confinement, she adorned herself for those who might seek her hand. Abu al-Sanabil ibn Ba'kak came to her and said: "Why do I see you adorned? Perhaps you hope for marriage? By Allah, you are not a widow until four months and ten days have passed." Subay'ah said: "When he said that to me, I gathered my garments upon me when evening came and went to the Messenger of Allah (peace be upon him) and asked him about that. He gave me a legal opinion that I was lawful [to marry] when I had given birth, and he commanded me to marry if I wished."