It is narrated from Hazrat Anas (may Allah be pleased with him) that once the Prophet (peace and blessings be upon him) shook a tree, but its leaves did not fall; even after shaking it a second time, the leaves did not fall. However, when he shook it a third time, its leaves began to fall. The Prophet (peace and blessings be upon him) said that by saying "Subhan Allah, Alhamdulillah, La ilaha illallah, and Allahu Akbar," sins fall away just as the leaves fall from a tree.