"Watch over your heart with all diligence, for from it flow the springs of life." -- Proverbs 4:23
Proverbs 23:7 puts it another way: in our usual slight misquotation, "As a man thinketh in his heart, so is he."
I remember a quote from a pastor, who credited it to Harry Truman: "What's down in the well comes up in the bucket." (Trying to track down that saying's origin, I find it's been ascribed to numerous people besides Truman, including a slightly different form by evangelist Vance Havner.) That puts Proverb's wisdom pretty well.
But I didn't realize until I started pondering and studying Proverbs 4:23 how often Jesus alludes to its wisdom:
"...how can you, being evil, speak what is good? For the mouth speaks out of that which fills the heart."
-- Matthew 12:34
"But the things that proceed out of the mouth come from the heart, and those defile the man." -- Matt. 15:18
"For from within, out of the heart of men, proceed the evil thoughts." -- Mark 7:21
"The good man out of the good treasure of his heart brings forth what is good; and the evil man out of the evil treasure brings forth what is evil; for his mouth speaks from that which fills his heart." -- Luke 6:45
Proverbs' take on man's spiritual identity is exactly that of Jesus: man's identity is always in God's moral terms...and shows in all that a man does, as either righteous or evil.
John puts that wisdom even more succinctly: "By this the children of God and the children of the devil are obvious (my emphasis: other translations say "manifest"): anyone who does not practice righteousness is not of God, nor the one who does not love his brother." (I John 3:10).
The set-up of the old joke is profoundly right: "There are only two kinds of people..."
