It is narrated from Sayyiduna Malik bin al-Huwayrith (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said to him and a companion of his: "When the time of prayer comes, give the adhan, then the iqamah, and let the elder of you two lead the prayer."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16689