An important principle enshrined in this Hadith says that courtesy is a virtue, because a refined mind cultivates good habits, performs good deeds, and shuns all that is bad and corrupt. Also, a simple and understandable principle is laid down about sin. Man feels the pricking of conscience over every bad deed and is also afraid of the reproach of fault-finders, provided he has not reached the lowest point of moral depravity. But a seared conscience is least disturbed even by a heinous and deadly sin or by public censure. We can understand it by the example of man's smelling sense. If it is not dead, man can feel a stink and repugnant odour. But a long association with a dung heap robs away one's smelling sense and feeling of refuse.