The Messenger of Allaah (peace and blessings of Allaah be upon him) said:
“The people should be led in prayer by the one who has most knowledge of the Qur’aan and has been reciting it for longer. If they are equal in their knowledge and reading of the Qur’aan, then they should be led by the one who made hijrah first. If they are equal with regard to hijrah, then they should be led by the one who is older…” (Narrated by Muslim, 1079).