Apply thine heart unto instruction, and thine ears to the words of knowledge.
Spiritual knowledge
I. Because of its own worth. A knowledge of the creation, its elements, laws, objects, extent, is valuable, but a knowledge of the Creator is infinitely more valuable. “This is life eternal, to know Thee, the only true God, and Jesus Christ, whom Thou hast sent.”
II. Because man is prone to overlook the importance of this knowledge. It is sad, that that which man requires most he cares least for, that the most priceless treasure is least valued.
III. Because to attain it there must be personal application. “Apply thine heart unto instruction.” It is a knowledge that cannot be imparted irrespective of the use of man’s own faculties. He must apply persistently, earnestly, devoutly. (Homilist.)
The heart and the ears
Observe the connection between the application of the heart and the ears. The heart open to sound advice or moral precept is yet shut to Christ and His doctrine. It is closed up in unbelief, prejudice, indifference, and the love of pleasure. A listless heart, therefore, produces a careless ear. But when the heart is graciously opened, softened, and enlightened, the attention of the ear is instantly fixed. This, indeed, is the Lord’s creative work; yet wrought by a God of order in the use of His own means. Awakened desire brings to prayer. Prayer brings the blessing. And precious then is every word of knowledge. (C. Bridges, M.A.)