Proverbs 9:10

The fear of the Lord [is] the beginning of wisdom
This shows who the wise men are, and in what true wisdom lies; no man is wise till he fears the Lord, and he that does so is a wise man, at least then he begins to be one; this is the principal part of wisdom, ( Proverbs 1:7 ) ; and is at the first of it; it is the beginning of grace; it is the first act of wisdom, or grace; or which appears as soon as a man is converted and caused to know wisdom in the hidden part; as repentance, faith, and love, quickly show themselves in one act or another, so does the fear of God; for the former are never without the latter; for fear is an awe and reverence of the divine Being, joined with love to him, trust in him, and a desire to serve and worship him in a right manner; no sooner is a man converted, but presently there is in him a fear of offending God, from a principle of love to him; for not a slavish but a filial fear is here intended; and the knowledge of the Holy [is] understanding:
either the knowledge of the Holy Ones, as the three divine Persons in the Godhead, who are so called, ( Joshua 24:19 ) ( Proverbs 30:3 ) ( Hosea 11:9 ) ; the knowledge of God the Father, who is holy in his nature and works; not a mere natural knowledge of him by the light of nature; nor a mere notional knowledge of him by revelation; not a legal knowledge of him as a lawgiver, and an offended Judge; but an evangelical knowledge of him in Christ, as his God and Father; and as the God of all grace in him; so as to have faith and hope in him, access unto him, and communion with him; this is right understanding: so the knowledge of Christ, God's Holy One; a knowledge of him in his person, offices, and grace; an inward knowledge of him, a spiritual acquaintance with him, so as to approve of him, believe in him, and appropriate him to one's self; this is to attain to a good degree of understanding: as likewise the knowledge of the Holy Spirit, the author of sanctification; of his person, and operations of grace; as a convincer and comforter; as a Spirit of illumination and faith, of regeneration and sanctification; and as the Spirit of adoption, and the earnest of glory; this is another branch of spiritual understanding. Moreover, such knowledge which holy men have, and which makes them so; and which holy men of God, moved by the Holy Ghost, have communicated in the sacred Scriptures, of which they are the penmen. The knowledge of holy things may also be meant; of the holy mysteries of religion, of the holy doctrines of the Gospel, which are all according to godliness, and teach men to live in a holy manner: the faith once delivered to the saints is a most holy faith, encourages and promotes holiness of heart and life; as the doctrines of God's everlasting love; eternal election; the unconditionality of the covenant of grace; redemption by Christ; conversion by efficacious grace; justification by Christ's righteousness; pardon by his blood; satisfaction by his sacrifice; and perseverance by his power: and now a knowledge of these things, not notional, but experimental, is understanding indeed; as well as a knowledge of holy and gracious experiences.