THINK NOT LIGHTLY OF EVIL
Mavamannetha papassa na mam tam agamissati
Udabindu nipatena udakumbho' pi purati
Purati balo papassa thokathokam'pi acinam.
Do not think lightly of evil, saying: 'It will not come to me. 'Even a water-pot is filled by the falling of drops. Likewise the fool, gathering it drop by drop, fills himself with evil. 
A bhikkhu, after using any piece of furniture such as a couch, a bench or a stool belonging to the monastery, would leave it outside in the compound, thus exposing it to rain and sun. When other bhikkhus chided him for his irresponsible behaviour, he would retort, 'I don't have the intention to destroy those things. After all, very little damage has been done.' And he continued to behave in the same manner. When the Buddha came to know about this, he sent for the bhikkhu and admonished him, 'Bhikkhu, you should not behave in this way; you should not think lightly of an evil, however small, because it will become big if you do it habitually'.