'Understand' in the Bible

Therefore speak I to them in parables; because seeing they see not, and hearing they hear not, neither do they understand.

And unto them is fulfilled the prophecy of Isaiah, which saith, By hearing ye shall hear, and shall in no wise understand; And seeing ye shall see, and shall in no wise perceive:

For this people's heart is waxed gross, And their ears are dull of hearing, And their eyes they have closed; Lest haply they should perceive with their eyes, And hear with their ears, And understand with their heart, And should turn again, And I should heal them.

And he called to him the multitude, and said unto them, Hear, and understand:

When therefore ye see the abomination of desolation, which was spoken of through Daniel the prophet, standing in the holy place (let him that readeth understand),