The fear of the LORD is the beginning of wisdom: and the knowledge of the holy is understanding.
– Proverbs 9:10
The beginning, or commencement, of wisdom is the reverent fear of God. This is thematic in Proverbs (Proverbs 1:7) and is taught elsewhere as well (Psalm 111:10). Wisdom is to hate evil and through the fear of the Lord we depart from it (Proverbs 8:13; 16:6). Holy fear leads to satisfaction and contentment (Proverbs 19:23). It brings us to safety and blessing (Proverbs 29:25; 28:14). The holy is interpreted variously by commentators and scholars. The Hebrew word is in the plural and is a term applied to God, angels, and saints. From the context, it seems sensible to understand it as referring to God here so that you have both the fear and the knowledge of God to be wisdom and understanding.