Maliks Muwatta Book 29, Hadith Number 85.

Section : Idda of Widows when Pregnant.

Yahya related to me from Malik from Hisham ibn ‘Urwa from his father that al-Miswar ibn Makhrama told him that Subaya al-Aslamiya gave birth a few nights after the death of her husband. The Messenger of Allah, may Allah bless him and grant him peace, said to her, “You are free to marry, so marry whomever you wish.”