Simple.--Literally, those who are open to good impressions and influences, but who also can be easily led astray. (Comp. Proverbs 8:5; Proverbs 14:15.)
Young man.--The Hebrew term is used of any age from birth to about the twentieth year.
Discretion.--Or rather, thoughtfulness; a word also used in a bad sense in Proverbs 12:2, and there translated "wicked devices."
to the young man knowledge and discretion; or "thought" (i); who wants both: this book will teach him the knowledge of things moral, civil, and religious: to think and act aright; how to behave and conduct himself wisely and discreetly before men; and be a means of forming his mind betimes for piety and religion; and of furnishing him with rules for his deportment in future life, in all the periods of it; and in whatsoever state and condition he may come into. A "young man may cleanse his way", Psalm 119:9, reform his manners, behave with purity and uprightness, by taking "heed" to the things herein contained.
(i) "cogitationem", Pagninus, Mercerus; "bonam cogitationem", Michaelis.