John 10:6

Yea, they are greedy dogs which can never have enough, and they are shepherds that cannot understand: they all look to their own way, every one for his gain, from his quarter.

Evil men understand not judgment: but they that seek the LORD understand all things.

They know not, neither will they understand; they walk on in darkness: all the foundations of the earth are out of course.

These things have I spoken unto you in proverbs: but the time cometh, when I shall no more speak unto you in proverbs, but I shall shew you plainly of the Father.

Jesus saith unto them, Have ye understood all these things? They say unto him, Yea, Lord.

Many shall be purified, and made white, and tried; but the wicked shall do wickedly: and none of the wicked shall understand; but the wise shall understand.

Our fathers understood not thy wonders in Egypt; they remembered not the multitude of thy mercies; but provoked him at the sea, even at the Red sea.

Many therefore of his disciples, when they had heard this, said, This is an hard saying; who can hear it?

They understood not that he spake to them of the Father.

Why do ye not understand my speech? even because ye cannot hear my word.

The Jews therefore strove among themselves, saying, How can this man give us his flesh to eat?

What manner of saying is this that he said, Ye shall seek me, and shall not find me: and where I am, thither ye cannot come?

But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.