(1) بَابُ مَا جَاءَ فِي إِجَازَةِ خَبَرِ الْوَاحِدِ الصَّدُوقِ فِي الأَذَانِ وَالصَّلاَةِ وَالصَّوْمِ وَالْفَرَائِضِ وَالأَحْكَامِ
Narrated Malik:
We came to the Prophet (ﷺ) and we were young men nearly of equal ages and we stayed with him for twenty nights. Allah's Messenger (ﷺ) was a very kind man and when he realized our longing for our families, he asked us about those whom we had left behind. When we informed him, he said, "Go back to your families and stay with them and teach them (religion) and order them (to do good deeds). The Prophet (ﷺ) mentioned things some of which I remembered and some I did not. Then he said, "Pray as you have seen me praying, and when it is the time of prayer, one of you should pronounce the call (Adhan) for the prayer and the eldest of you should lead the prayer. "
Reference: Sahih al-Bukhari 7246
In-book reference: Book 95, Hadith 1
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 91, Hadith 352