Sunan an-Nasa'i 852
سنن النسائي#852SahihIt was narrated from Hisham bin 'Urwah from his father that 'Abdullih bin Arqam used to lead his companions in prayer. The time for prayer came one day and he went to relieve himself then he came back and said:"I heard the Messenger of Allah (ﷺ) say: 'If any one of you feels the need to defecate, let him do that first, before he prays
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 10:76