"It was said to Ibn 'Abbas concerning a woman who gives birth one day after her husband died: 'Can she get married?' He said: 'No, not until the longer of the two periods has ended.' He said: 'Allah says: And for those who are pregnant (whether they are divorced or their husbands are dead), their 'Iddah (prescribed period) is until they lay down their burden.' He said: 'That only applies in the case of divorce.' Abu Hurairah said: 'I agree with my brother's son' --meaning, Abu Salamah. He sent his slave Kuraib and told him: 'Go to Umm Salamah and ask her: Was this the Sunnah of the Messenger of Allah?' He came back and said: 'Yes, Subai'ah Al-Aslamiyyah gave birth twenty days after her husband died, and the Messenger of Allah told her to get married, and Abu As-Sanabil was one of those who proposed marriage to her.'" (Using translation from Nasāʾī 3511)
قِيلَ لِابْنِ عَبَّاسٍ فِي امْرَأَةٍ وَضَعَتْ بَعْدَ وَفَاةِ زَوْجِهَا بِعِشْرِينَ لَيْلَةً أَيَصْلُحُ لَهَا أَنْ تَزَوَّجَ؟ قَالَ لَا إِلَّا آخِرَ الْأَجَلَيْنِ قَالَ قُلْتُ قَالَ اللهُ وَتَعَالَى {وَأُولَاتُ الْأَحْمَالِ أَجَلُهُنَّ أَنْ يَضَعْنَ حَمْلَهُنَّ} [الطلاق 4] فَقَالَ إِنَّمَا ذَلِكَ فِي الطَّلَاقِ وَقَالَ أَبُو هُرَيْرَةَ أَنَا مَعَ ابْنِ أَخِي يَعْنِي أَبَا سَلَمَةَ فَأَرْسَلَ غُلَامَهُ كُرَيْبًا فَقَالَ ائْتِ أُمَّ سَلَمَةَ فَسَلْهَا هَلْ كَانَ بِهَذَا سُنَّةٌ مِنْ رَسُولِ اللهِ ﷺ؟ فَجَاءَهُ فَقَالَ قَالَتْ نَعَمْ سُبَيْعَةُ الْأَسْلَمِيَّةُ وَضَعَتْ بَعْدَ وَفَاةِ زَوْجِهَا بِعِشْرِينَ لَيْلَةً «فَأَمَرَهَا رَسُولُ اللهِ ﷺ أَنْ تَزَوَّجَ فَكَانَ أَبُو السَّنَابِلِ فِيمَنْ يَخْطُبُهَا»