It was narrated that Malik bin Al-Huwairith said:"I came to the Prophet (S.A.W) with a cousin of mine" - on an another occasion he said: "with a companion of mine" - "and he said: 'When the two of you travel, call the Adhan and the Iqamah, and let the older of you lead the prayer

English translation · Sunan an-Nasa'i