It is narrated from Abu Tamimah Hajimi, who reports from the back seat of the Holy Prophet Muhammad (peace and blessings be upon him), that he was sitting behind the Prophet (peace and blessings be upon him) on his mount. Suddenly, when the Prophet’s (peace and blessings be upon him) mount slipped, he said:“May the devil be ruined.”The Prophet (peace and blessings be upon him) said:“Do not say this. In this way, he considers himself great, so much so that he swells with joy until he becomes as big as a mountain and says, ‘I made him fall by my strength.’ But when you say ‘Bismillah’ (In the name of Allah), he becomes small, until he is as little as a fly.”