Mukhtasar Bukhari

Sayyiduna Malik bin Huwairith (may Allah be pleased with him) says: We came to the Prophet Muhammad (peace and blessings of Allah be upon him) and stayed in his company for twenty nights and days, and the Messenger of Allah (peace and blessings of Allah be upon him) was gentle-hearted and kind. When he (peace and blessings of Allah be upon him) realized that we were longing to return to our families, he (peace and blessings of Allah be upon him) said: "Return and stay among your people, teach them, command them (to do good), and establish prayer. When the time for prayer comes, let one of you give the call to prayer (adhan), and let the eldest among you lead the prayer."

Sayyiduna Malik bin Huwairith (may Allah be pleased with him) says that two persons came to the Prophet (peace and blessings of Allah be upon him) with the intention of traveling, so the Prophet (peace and blessings of Allah be upon him) said to them: "When you set out (and the time for prayer comes), then give the adhan, then say the iqamah, and after that, the elder among you should lead you in prayer."