Musannaf Ibn Abi Shayba 3:3138

Khalid ibn Makhlad narrated to us, he said: Kathir ibn Abdullah al-Muzani narrated to us, from his father, from his grandfather, he said: I heard the Messenger of Allah, may Allah bless him and grant him peace, saying regarding Friday: "There is an hour of the day in which a servant does not ask for anything except that he is given his request." It was said: "Which hour is it?" He said: "From when the prayer is established until it is finished."