then I can answer anyone who treats me with contempt.
Strange title, eh? Those words are an old (from the 1400's --- the medieval era) proverb, and they imply that someone who shows good behavior, wise judgement, and love of God early in life, will probably not continue in those traits later in life.
Oh, how we should strive to be young saints that progress to be old angels!! Then we can prove that proverb wrong!
Solomon is speaking here in his role as a father, and asking for his son to show wisdom. He gives two reasons for this request . . .
First, Solomon says that if his son is wise, it will bring joy to his (Solomon's) heart. All of us who are parents can vouch for the fact that when our children mature and make wise choices it truly does make us happy, and it brings us joy. To see your child (whether 18, 48, or older!) use the knowledge and skills that you helped to impart to him or her, and also use the discernment and wisdom that we pray they will have, is something that will bring satisfaction to us. We can "rest easy" with the knowledge that they can take care of themselves, their spouses, and their children, and that they will bring glory to God.
Solomon's second reason for his request is that he wants his son to do good, and to be wise, so that no one can say, "You didn't do a good job of raising him." One of the translations that I looked up implied that the son would be the one who would answer the accuser; his words and actions would be answer enough. He would then be a comfort and a credit to his father.
To make this apply to our lives, are we a credit to our earthly fathers? Do we bring joy to their hearts? And then, with more eternal meaning --- are we a credit to our heavenly Father? When someone reproaches us for a stand that we take, do we graciously explain that our choices are guided by our knowledge of Him and His word?
"So I will have an answer for him who reproaches me, For I trust in Your word." Psalm 119:42
Using the wisdom that we have learned in our studies will bring joy to His heart. I can't think of a better reason to seek, and then to use, that wisdom.