William Burkitt on Mark 10:20

This assertion of the young man might be very true, according to the Pharisees' sense and interpretation of the law, which condemned only the gross outward act, not the inward lust and motion of the heart. An outside obedience to the law this young man had performed; this made him think well of himself, and conclude the goodness of his own condition.

Learn hence, How prone men are to think the best of themselves, and to have too high an opinion of their own goodness and righteousness before God: All these things have I kept from my youth. It is a natural corruption in men to think to well of themselves, and of their own goodness and righeousness before God; but it is very dangerous and fatal so to do.