Sahih al-Bukhari 658
صحيح البخاري#658SahihNarrated Malik bin Huwairith:Prophet said (to two persons), "Whenever the prayer time becomes due, you should pronounce Adhan and then Iqama and the older of you should lead the 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 al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 10:52