(39) بَابُ: {وَأُولاَتُ الأَحْمَالِ أَجَلُهُنَّ أَنْ يَضَعْنَ حَمْلَهُنَّ}
Narrated Al-Miswer bin Makhrama:
Subai'a Al-Aslamiya gave birth to a child a few days after the death of her husband. She came to the Prophet and asked permission to remarry, and the Prophet (ﷺ) gave her permission, and she got married.
Reference: Sahih al-Bukhari 5320
In-book reference: Book 68, Hadith 69
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 63, Hadith 241