When someone has good virtue, or sīla, they give up doing bad things and they only do good things. The Supreme Buddha taught that sīla is the foundation of all wholesome qualities. That means that if we develop good sīla, then it will be easy to develop other good qualities like samādhi (concentration) and paññā (wisdom).
For lay people, the Buddha gave the Five Precepts to keep every day for as long as they live. Because he knew that also practicing renunciation was good for lay people, he also encouraged them to keep the Eight Precepts.
Three of the factors of the Noble Eightfold path are part of sīla: Right Speech, Right Action, and Right Livelihood.
In the Puññakiriyavatthu Sutta, the Buddha explained that sīla is one of the three grounds for making merit, along with dāna (giving), and bhāvana (meditation).
In the Abhisanda Sutta, the Buddha said in this way how virtue is one of the streams of merit:
“Furthermore, a noble disciple has the virtue that is loved by the noble ones, unbroken, flawless, unblemished, not caught up in craving, freed from wrong views, praised by wise people and leading to concentration. This is the fourth kind of stream of merit, stream of wholesomeness that generates happiness.Abhisanda Sutta, SN 55.31
The Buddha also taught about virtue using similes in the Dhammapada:
54. The scent of flowers does not go against the wind. The scent of sandalwood, jasmine, and rosebay does not go against the wind. But the scent of a grateful person does travel against the wind. The scent of his virtues spreads in all directions.
55. Of all the fragrances—sandalwood, rosebay, water lily, and jasmine—the fragrance of virtue is the sweetest.
56. Slight is the scent of rosebay or sandalwood, but the scent of the virtuous is supreme, drifting even to heaven.
57. The liberated ones are virtuous and practice the Dhamma diligently. They are freed from suffering by the realization of the Noble Truths. Māra never finds the path by which they are liberated.Dhammapada, Puppha Vagga
One of the Supreme Buddha’s Arahant disciples named Sīlava had this to say about virtue:
608. One should diligently practice virtue in this Buddha’s path. Here in this world, well practiced virtue brings all success.
609. A wise person should practice virtue desiring three types of happiness: praise, the gaining of wealth, and rejoicing in heaven after death.
610. By his restrained life, a virtuous person acquires many friends. But the unvirtuous person is separated from his friends because of his evil actions.
611. The unvirtuous person only gains a bad reputation and blame. The virtuous person always gains a good reputation, fame and praise.
612. Virtue is the foundation and base for wholesome qualities. Virtue is like a mother for all good qualities. Virtue is the foremost of all good qualities. Therefore, one should make one’s virtue pure.
613. The mind is like the great ocean. Virtue is like its beach. Virtue, the dock of merit of all Buddhas, gives joy and restraint. Therefore, one should make one’s virtue pure.
614. Virtue is an incomparable power. Virtue is the supreme weapon. Virtue is the best ornament. Virtue is a marvelous armour.
615. Virtue is a very mighty bridge. Virtue is an unsurpassed perfume. Virtue is the best scent which spreads in all directions.
616. Virtue is the supreme food for the journey. Virtue is the foremost source of wealth for a journey. Virtue is the best vehicle in which one can travel in all directions.
617. An evil person gets blamed in this world and after death he has to suffer having being born in hell. That fool falls into suffering everywhere due to lack of virtue and an unstill mind.
618. A well behaved person obtains fame in this world and after death is happy in heaven. That wise, energetic person is happy everywhere due to his virtuous behavior and a perfectly still mind.
619. Virtue is great in this Dhamma path but wisdom is the greatest. One can achieve victory among humans and gods through one’s virtue and wisdom.Verses of Arahant Sīlava
You can learn much more about sīla by reading more suttas on SuttaFriends.org.