Sahih Muslim 837
صحيح مسلم#837SahihIbn Umar reported:When the Muslims came to Medina, they gathered and sought to know the time of prayer but no one summoned them. One day they discussed the matter, and some of them said: Use something like the bell of the Christians and some of them said: Use horn like that of the Jews. Umar said: Why may not a be appointed who should call (people) to prayer? The Messenger of Allah (ﷺ) said: O Bilal, get up and summon (the people) to prayer
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 4:1