Passage cross-references.

Apply thine heart unto instruction, and thine ears to the words of knowledge.

So teach us to number our days, that we may apply our hearts unto wisdom.

My son, forget not my law; but let thine heart keep my commandments:

To receive the instruction of wisdom, justice, and judgment, and equity;

So that thou incline thine ear unto wisdom, and apply thine heart to understanding; …

I applied mine heart to know, and to search, and to seek out wisdom, and the reason of things, and to know the wickedness of folly, even of foolishness and madness:

My son, attend unto my wisdom, and bow thine ear to my understanding: …

Hear instruction, and be wise, and refuse it not. …

All this have I seen, and applied my heart unto every work that is done under the sun: there is a time wherein one man ruleth over another to his own hurt.

While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him.

He taught me also, and said unto me, Let thine heart retain my words: keep my commandments, and live. …

When I applied mine heart to know wisdom, and to see the business that is done upon the earth: (for also there is that neither day nor night seeth sleep with his eyes:)

Incline your ear, and come unto me: hear, and your soul shall live; and I will make an everlasting covenant with you, even the sure mercies of David.