Musnad Ahmad 1098:3

Abdullah ibn al-Harith narrated to us, al-Dahhak narrated to me, from Abu al-Nadr, from Abu Salamah ibn Abd al-Rahman, from Abdullah ibn Salam, who said: I said while the Messenger of Allah (peace and blessings of Allah be upon him) was sitting: "We find in the Book of Allah that on Friday there is an hour; no Muslim servant coincides with it while he is in prayer, asking Allah the Almighty for something, but He gives him what he asked for." The Messenger of Allah (peace and blessings of Allah be upon him) gestured, saying: "A portion of an hour." I said: "The Messenger of Allah has spoken the truth." Abu al-Nadr said: Abu Salamah said: I asked him, "Which hour is it?" He said: "The last hours of the day." I said: "It is not a time of prayer." He said: "Yes, indeed, the Muslim servant is in prayer when he prays, then sits in his place of prayer, with nothing detaining him except the waiting for the prayer."