Sila is compared to a stream of clear water, because it can wash off the stains of wrong actions which can never be removed by the waters of all other rivers. Sila is like sandalwood, because it can remove the fever of the defilements just as sandalwood (according to ancient Indian belief) can be used to allay bodily fever. Again sila is like an ornament made of precious jewels because it adorns the person who wears it. It is like a perfume because it gives off a pleasant scent, the “scent of virtue,” which unlike ordinary perfume travels even against the wind. It is like moonbeams because it cools off the heat of passion as the moon cools off the heat of the day. And sila is like a staircase because it leads upwards by degrees — to higher states of future existence in the fortunate realms, to the higher planes of concentration and wisdom, to the supernormal powers, to the paths and fruits of liberation, and finally to the highest goal, the attainment of nibbana.
By Bhikkhu Bodhi, Access to Insight