Musnad Ahmad

It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that a man came to the presence of the Messenger and asked, "What do you command me?" The Noble Prophet (peace and blessings be upon him) said, "Treat your mother well." He asked, "Then who?" He said, "Your mother." He asked, "Then who?" He said, "Your mother." The fourth time he said, "Your father."