What is the preliminary duty of the Sangha? The venerables should declare their purity. I will recite the Monastic Code. Everyone present should listen to it and attend carefully. Anyone who has committed an offense should reveal it. If you haven’t committed any offense, you should remain silent. If you are silent, I will regard you as pure. Just as one responds when asked individually, so too, an announcement is made three times in this kind of gathering. If a monk remembers an offense while the announcement is being made up to the third time, but doesn’t reveal it, he is lying in full awareness. Lying in full awareness is called an obstacle by the Buddha.