Musnad Abu Ya'la al-Mawsili 236:1

Uthman ibn Abi Shaybah narrated to us, Abu Mu'awiyah narrated to us, Hisham ibn Urwah narrated to us, from his father, from Asim ibn Umar, from al-Miswar ibn Makhramah, who said: Subay'ah gave birth a few days after the death of her husband. She came to the Messenger of Allah (may Allah bless him and grant him peace) and sought his permission to marry, so he gave her permission.