Musnad Ahmad

It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that once I set out towards Mount Tur... Then he mentioned the complete hadith. Hazrat Abu Hurairah (may Allah be pleased with him) says that after that I met Hazrat Abdullah bin Salam (may Allah be pleased with him), so I told him about my sitting with Ka'b and also narrated the hadith I had mentioned regarding the day of Friday, and said that Ka'b said this happens only once in the whole year. Hazrat Abdullah bin Salam (may Allah be pleased with him) said Ka'b made a mistake; this happens every Friday. Hazrat Ibn Salam (may Allah be pleased with him) said, "By Him in Whose hand is the life of Abdullah bin Salam, I know that hour." I said to him, "O Abdullah! Please tell me about it as well." He said, "It is the last hour of the day of Friday." I said, "But during the prayer, no one can get it (because it is prohibited at that time)." He said, "Did you not hear the Prophet (peace and blessings of Allah be upon him) say that whoever waits for the prayer, he is counted as being in prayer until he prays?" I said, "Why not." He said, "Then that is it."