'self-confidence' of a Buddha is fourfold.
He is confident:
1. to have attained to a perfect Enlightenment of which it cannot be said that it omits anything essential to it;
2. to have destroyed all cankers (āsava), leaving none that can be said to be undestroyed by him;
3. that what were declared by him as obstacles to liberation are undeniably such;
4. that his teaching fulfils its purpose of actually leading to final liberation from suffering.
See A.IV.8; VII.58; M.12.