Proverbs 22:20

Have not I written to thee excellent things— Many of the ancient versions read threefold things, in which they are followed by Schultens and Grotius. The Jews distinguished philosophy under three branches; morality, physics, and divinity. Solomon wrote in all these branches, as appears from 1 Kings 4 but most of his writings are lost. This and the book of Ecclesiastes contain what he wrote in morality or ethics. His discourses on plants and animals relate to physics, and the Canticles belong to allegorical divinity. I should rather, however, understand the word according to our version; or, more properly, "Words fit for a prince to speak, and the best men in the world to hear, and therefore truly excellent." See Patrick and Calmet.