The psalmist appeals to the Lord that the Lord would keep him from “presumptuous sins” (Psalm 19:13, NKJV). What are presumptuous sins? The NET reads, “keep me from committing flagrant sins.” One Bible expositor said the word conveys the idea of pride, sins that proceed from self-confidence, from one’s ability to understand and direct a course of action (Cf. Barnes Notes). Presumptuous sins are directly related to what is also known as “high-handed” sins (Numbers 15:30).
The psalmist appealed to the Lord, asking the Lord to keep him back from such things. How might this occur? In the same Psalm, the psalmist said of that which came from the Lord, “The law of the Lord is perfect, converting the soul; the testimony of the Lord is sure, making wise the simple” (19:7). In these words we have our answer. The one who would be prevented from committing presumptuous sins will be the same one who is taught and constrained by that which is perfect. Once one steps outside the bounds of that which is perfect, then trouble begins to brew.
To varying degrees presumptuous sins are a struggle for everyone; the Christian is not immune. Whether the presumption is on a small scale (weakness of the flesh) or on a larger scale (rebellion), the struggle to satisfy self is constant. For a large portion of mankind there is a lack of awareness of them even committing presumptive sins! This is not surprising, but it is terribly disappointing when Christians are also not aware. They are not aware, perhaps, because they have refused or neglected to allow the law of the Lord to teach them about the right and holy way. Many times, this denial of theirs turns into a burial. RT