Musannaf Ibn Abi Shayba 3:3738

Waki' narrated to us, he said: Bashir ibn Sulayman narrated to us, from Yahya ibn Bistam al-Tamimi, from al-Dahhak, he said: A slave shall not lead [the prayer] while there is a free man among them, and one who has not performed Hajj shall not lead [the prayer] while there is one among them who has performed Hajj.