Mat 7:8

For the one who asks, receives. The one who seeks, finds. The one who knocks, enters.

Mat 13:16

But blest are your eyes because they see and blest are your ears because they hear.

Mat 15:10

Give ear and try to understand.

Mark 4:13

You do not understand this parable? How then are you going to understand other figures like it?

Mark 8:17, 18

Do you still not see or comprehend? Are your minds completely blinded? Have you eyes but no sight? Ears but no hearing?

Luke 8:16-18

No one lights a lamp and puts it under a bushel basket or under a bed; he puts it on a lamp stand so that whoever comes in can see it. There is nothing hidden that will not be exposed, nothing concealed that will not be known and brought to light. Take heed, therefore, how you hear: to the man who has, more will be given; and he who has not, will lose even the little he thinks he has. (knowledge)

Luke 12:56, 57

You hypocrites! If you can interpret the portents of the earth and sky, why can you not interpret the present time? Tell me, why do you not judge for yourselves what is just?

John 7:24

Stop judging by appearances and make an honest judgment.

John 8:43

Why do you not understand what I say?