Malik bin al-Huwayrith (may Allah be pleased with him) says: My companion and I came to the Prophet (peace and blessings be upon him). When we intended to return from him (peace and blessings be upon him), he (peace and blessings be upon him) said to us: "When the time of prayer comes, give the call to prayer (adhan) and the iqamah, then let the elder of you two lead the prayer."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4999