It is narrated from a freed slave of Hazrat Usama bin Zaid (may Allah be pleased with him) that one day he was with Hazrat Usama (may Allah be pleased with him) in Wadi Qura in search of his wealth. It was the habit of Hazrat Usama (may Allah be pleased with him) that he used to fast on Mondays and Thursdays. His slave asked him, "Despite being so old and weak, why do you observe the fast of Monday and Thursday so regularly?" He replied, "The Holy Prophet (peace and blessings be upon him) also used to fast on Mondays and Thursdays. Someone asked him the reason for this, so the Holy Prophet (peace and blessings be upon him) said, 'On Mondays and Thursdays, the deeds of people are presented.'"