Musannaf Ibn Abi Shaybah 24156 — Asking permission to enter market

Ibn Awn said: I was with Mujahid in the market of Kufah, and the tents (platforms) of the tailors were set up facing the market that adjoined the houses of Banu al-Bakka. He (may Allah have mercy on him) said: "Sayyiduna Ibn Umar (may Allah be pleased with them both) would ask their permission for this." I said: "How would he do it?" He said: "He would say: 'As-salamu alaykum, may I enter?' and then he would enter."