keséí†l (lysiK], 3684), “stupid or dull person”. The term is found 70 times in the Old Testament. All the cases are in the wisdom literature, except 3 that are in the Psalms. The keséí † l is “insolent” in matters of religion and “stupid or dull” in living wisely the religion that he professes. Psa 92:6 particularly highlights the first emphasis: “The foolish man does not know, and the fool does not understand this.” The psalmist describes an enemy of God who knew him and his Word, but seeing the wicked prospering he came to approve of his lifestyle (Psa 92:7). The keséí † l has knowledge of God, but he does not know how to properly evaluate or understand what he knows. The second emphasis is very prominent in Wisdom literature in particular: “How long, O simple ones, will you love simplicity, and scoffers will desire to scoff, and fools will hate science?” (Pro 1:22 KJV). In this context the people referred to reject the requirements and teachings of wisdom. Since in the Bible wisdom is the practical evidence of a religion, it can be noted from the above that even in religious contexts there is religious insolence. Kesel means “stupidity; unconcern; confidence”. The name appears 6 times. He means “stupidity” in Ec 7.25 and “confidence” in Pro 3:26 (rva). This last meaning also appears in Job 31:24 “If I put gold as an object of my trust.”
Source: Vine Old Testament Dictionary