What does it mean to buy the truth and sell it not? We see that instruction in Proverbs 23:  23, buy the truth and sell it not.  To buy connotes, to obtain or acquire something in exchange for payment to sell is to offer something in exchange for money or some other valuables. Truth can be said to be that which is consistent with the mind will character, glory, and the being of God. And He is a fountain of truth, all the parts of the Lord are mercy and truth to such as keep his covenant and his testimonies. Some 25 vs 10 looks, also at   John 1: 17, John 4: 24, Psalm 86:15. Psalm 100: 5  and  Psalm 108: 4 So when he says, buy the truth and sell it. Not what he's saying is to obtain and acquire the truth. That which is consistent with the being of God, with the mind of God, with the will of God in exchange for some form of payment