"Subai'ah delivered twenty-three or twenty-five days after her husband had died. So when she was ready (finished post-natal bleeding) she adorned herself for marriage, but she was rebuked for doing that, so it was mentioned to the Prophet and he said: "If she has done that then her time has come.'"  

وَضَعَتْ سُبَيْعَةُ بَعْدَ وَفَاةِ زَوْجِهَا بِثَلاَثَةٍ وَعِشْرِينَ أَوْ خَمْسَةٍ وَعِشْرِينَ يَوْمًا فَلَمَّا تَعَلَّتْ تَشَوَّفَتْ لِلنِّكَاحِ فَأُنْكِرَ عَلَيْهَا ذَلِكَ فَذُكِرَ ذَلِكَ لِلنَّبِيِّ ﷺ فَقَالَ إِنْ تَفْعَلْ فَقَدْ حَلَّ أَجَلُهَا حَدَّثَنَا أَحْمَدُ بْنُ مَنِيعٍ حَدَّثَنَا الْحَسَنُ بْنُ مُوسَى حَدَّثَنَا شَيْبَانُ عَنْ مَنْصُورٍ نَحْوَهُ قَالَ وَفِي الْبَابِ عَنْ أُمِّ سَلَمَةَ  

Abu Hurairah, Ibn Abbas and Abu Salamah bin Abdur-Rahman mentioned the pregnant women whose husband died and she gave birth after the death of her husband. So Ibn Abbas said: "She observes Iddah until the end of the two terms." Abu Salamah said: "Rather, she is allowed when she gives birth." Abu Hurairah said: "I am with my nephew," meaning Abu Salamah.So he sent a message to Umm Salamah the wife of the Prophet. She said: "Subai'ah Al-Aslamiyyah gave birth a short time after her husband died, so she sought the judgment of the Messenger of Allah and he ordered her to get married."  

وَقَالَ أَبُو سَلَمَةَ بَلْ تَحِلُّ حِينَ تَضَعُ وَقَالَ أَبُو هُرَيْرَةَ أَنَا مَعَ ابْنِ أَخِي يَعْنِي أَبَا سَلَمَةَ فَأَرْسَلُوا إِلَى أُمِّ سَلَمَةَ زَوْجِ النَّبِيِّ ﷺ فَقَالَتْ قَدْ وَضَعَتْ سُبَيْعَةُ الأَسْلَمِيَّةُ بَعْدَ وَفَاةِ زَوْجِهَا بِيَسِيرٍ فَاسْتَفْتَتْ رَسُولَ اللَّهِ ﷺ فَأَمَرَهَا أَنْ تَتَزَوَّجَ