Musannaf Ibn Abi Shaybah

Hazrat Zaid bin Aslam narrates from his father, who says that I was walking with Hazrat Umar bin Khattab (may Allah be pleased with him). He saw a fallen date and said, "Pick it up." I asked, "What should I do with this date?" Hazrat Umar (may Allah be pleased with him) said, "Dates are gathered one by one." So I picked it up. Then he (may Allah be pleased with him) passed by a heap of dates and said, "Throw this date here."