Sahih al-Bukhari 630
صحيح البخاري#630SahihNarrated Malik bin Huwairith:Two men came to the Prophet (ﷺ) with the intention of a journey. The Prophet (ﷺ) said, "When (both of) you set out, pronounce Adhan and then Iqama and the oldest 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: 10:27