§ 02 · King James Bible
Mark 4:12
That seeing they may see, and not perceive; and hearing they may hear, and not understand; lest at any time they should be converted, and their sins should be forgiven them.
Simple English
So they can look but not really understand, and listen but not truly comprehend. This is so they never fully realize their mistakes, and thus won't change, keeping their sins unforgiven.
* Work in progress - there may be occasional inaccuracies