Sunan Ibn Majah 1400
سنن ابن ماجه#1400SahihIt was narrated that Ibn ‘Abbas said:“Your Prophet (ﷺ) was enjoined to do fifty prayers but he returned to your Lord to make (i.e., reduce) them to five prayers.”
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 Lighairihi
Shuaib Al ArnautSahih Lighairihi
Zubair Ali ZaiSahih
In-book reference: 5:598