Musannaf Ibn Abi Shaybah

Hazrat Salamah bint Af’a says that I was with some women in the company of Hazrat Aisha (may Allah be pleased with her), and she was saying that the day of Friday is like the day of Arafah; in it, there is an hour during which the doors of mercy are opened. We asked, “Which hour is that?” She replied, “When the muezzin gives the call to prayer (adhan).”