What is the “they” (1992) in this verse? You need to look back to verse 20.
(Proverbs 4:20 KJV) My son, attend to my words; incline thine ear unto my sayings.For us this would include the council of the entire Bible since it is the written word to us. Solomon makes a big promise. The promise is both literal and figurative. It is temporal and eternal. It is personal and plural. By following the teachings of the Bible we change our lives and the lives of our family.
“Life” (2425b) can be physical. It can be eternal. Both work. “Health” (4832) also runs the gamut. This is the mystery of simple words on paper or out of the mouth when we listen and apply. This is why it is so important to have a steady diet of such and ordinary experience.
So? Such a dull lesson. Listen. Learn. Apply. Live. Such an incredible effect. Life and health.