Even to thee - The wide general character of the teaching does not hinder its being a personal message to every one who reads it.

That thy trust may be in the Lord, I have made known, etc. -
III. The End for which the wise man gives these instructions: -
1. "That thy trust may be in the Lord." That thou mayest acknowledge Him as the Fountain of all good; and refer every thing to him.
2. That this end may be accomplished, the instructions are specific and particular: "I have made known to thee, even to thee."
3. And this has not only been done in times past, "I have made known:" but even in the present, "I have made known this day!"
IV. An appeal is made to the person himself relative to the matter and importance of the teaching.
1. "Have I not written to thee excellent things;" שלשים shalishim, literally threefold, thrice, in three different ways; which some think refers to his three books: -
1. Song of Solomon.
2. Koheleth, or Ecclesiastes.
3. Proverbs.
Others, understanding it of the voice of Divine wisdom, suppose the three grand divisions of the sacred oracles are intended; viz.,
1. The Law;
2. The Prophets;
3. The Hagiographa.
And others interpret it of the three grand intellectual sciences: -
1. Morality, or Ethics.
2. Natural Philosophy, or Physics.
3. Theology, or the science of Divine things as reported in the Scriptures. But Solomon's books of Natural Philosophy are lost.
And lastly, some of the rabbins and some Christians find in these shalishim the three senses of Scripture:
1. Literal;
2. Figurative;
3. Allegorical.
After all, as we know the term thrice was used as the term seven, a certain number for an uncertain, (see Amos 1:11; 2-Corinthians 12:8), it may mean no more here than, I have written to thee often. But perhaps it is safer to apply it to the Scriptures, and the excellent doctrines they contain: for שלשים shalishim signifies also excellent, princely things; things which become a king to speak. Indeed, it would not be difficult to prove that there is not one important art or science which is not alluded to in the Holy Scriptures, and used to illustrate and inculcate heavenly truths.
2. These excellent, princely, or threefold teachings, consist of two grand parts:
1. Counsels, מעצות moetsoth, from יוץ yaats, to give advice, counsel, or information. These (1) show thee what thou shouldst know; and (2) advise thee what thou shouldst do.
2. Knowledge, דעת daath, from ידע yada, to perceive, or feel by means of the senses and internal perception; viz., what should be felt, experienced, known to be true by mental perception, and by their influence on the heart and affections.
V. All this is done to give the pupil the fullest satisfaction, and most plenary evidence concerning the truths of God.

That thy trust may be in (m) the LORD, I have made known to thee this day, even to thee.
(m) He shows what the end of wisdom is: that is, to direct us to the Lord.

That thy trust may be in the Lord,.... By means of the words of the wise, or doctrines of the Gospel, faith in Christ is first had; men are directed and encouraged hereby to believe in him; and by the same means faith is increased, confirmed, and established. This is the end of penning the Scriptures, and of the Gospel ministry, as follows:
I have made known to thee this day, even to thee; the said words and doctrines in the ministry of the word, by the Spirit of wisdom and revelation in the knowledge of them; giving not only a notional, but a spiritual and experimental knowledge of them. The Lord has particular persons to whom he will make known these things in a saving way; it is "to thee, even to thee"; and to everyone whom God has chosen, and Christ has redeemed: and he has particular times and seasons for it, "this day"; which is a time of life and love; when darkness is removed, and the light of grace shines, and makes it day; and may respect the whole Gospel dispensation, which is the accepted time and day of salvation.

That . . . Lord--This is the design of the instruction.