Sunan Ibn Majah 2083
سنن ابن ماجه#2083SahihIt was narrated that 'Amr bin 'As said:"Do not corrupt the Sunnah of our Prophet Muhammad (ﷺ). The waiting period of an Umm Walad is four months and ten (days)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Zubair Ali ZaiHasan
In-book reference: 10:68