Sīla is the observance of physical and verbal actions. It is said in the Visuddhimagga: “A wise man, after establishing well in virtue, develops concentration, and understanding.”. Sīla serves as a firm foundation towards the attainment of insight knowledge which can lead one to Nibbāna. a combination of moral shame (hiri) and conscience (otappa).
It is called Sīla in the sense of composing. The term “Sīla” includes other similar terms such as restraint (saṁvara) and non-aggression (civitikama). The characteristic of Sīla is composing; its function (rasa) has a double sense: (1) action to stop misconduct and (2) achievement as the quality of blamelessness. Its manifestation (paccutthāma) is
When one observes morality (Sīla), one controls oneself from doing misdeeds, and speaking badly. Without morality, he tends to do misdeeds and speak wrongly. As a consequence, he will fall down to the four Apāyas, where there is no compassion and love, no tolerance and reasoning, no intellect and moral restraint in thoughts, words and deeds.
Morality is for (1) lay men, (2) novices (Samanera), and (3) Monks (Bhikkhus) and Nuns (Bhikkhunī). An average lay man usually observes the five precepts or eight precepts or abstains from the ten evil actions and cultivates the ten meritorious deeds and ten perfections. A novice has to observe the ten precepts, adding to 75 rules of training (Sekhiya). In Theravada tradition, a Buddhist Monk (Bhikkhu) has to observe 227 disciplinary rules (Pātimokkha). A Bhikkhunī has to observe 311 rules. In Mahayana tradition has a little difference, Bhikkhu receives 250 precepts, and Bhikkhuni has to observe 348 precepts.
The fame of virtuous person can spread in all directions. He enters any assembly without fear and hesitation. He dies unconfused and after his death he will be reborn in a happy realm. It is said in the Dhammapada:
“The scent of flowers cannot go against the wind,
fragrance of the virtuous person blows against the wind;
the virtuous man pervades every direction”.
In brief, each and everyone should observe morality, then we can attain Nibbāna sooner or later.