The Chapters on Divorce
10/7. Chapter:
When a pregnant widow gives birth, it is permissible for her to remarry
Sunan Ibn Majah
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ مُسْلِمٍ، عَنْ مَسْرُوقٍ، عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ، قَالَ وَاللَّهِ لَمَنْ شَاءَ لاَعَنَّاهُ لأُنْزِلَتْ سُورَةُ النِّسَاءِ الْقُصْرَى بَعْدَ أَرْبَعَةِ أَشْهُرٍ وَعَشْرًا .
It was narrated that' Abdullah bin Mas'ud said: "By Allah, for those who would like to go through the process of praying for Allah's curse to be upon the one who is wrong, the shorter Surah concerning women[l] was revealed after (the Verses[2] which speak of the waiting period of) four months and ten (days)." [1] (65:40), [2] (2:234)
Reference : Sunan Ibn Majah 2030In-book reference : Book 10, Hadith 15English translation : Vol. 3, Book 10, Hadith 2030