Solomon
Proverbs 3:8ESV·traditional attribution

It will be healing to your flesh and refreshment to your bones.

Matthew Henry Presbyterian @wholebiblehenry

We have here before us three exhortations, each of them enforced with a good reason: - I. We must live in a humble and dutiful subjection to God and his government (Pro 3:7): "Fear the Lord, as your sovereign Lord and Master; be ruled in every thing by your religion and subject to the divine will." This must be, 1. A humble subjection: Be not wise in thy own eyes.

Commenting on Proverbs 3:7-12

John Gill Reformed Baptist @doctorgill

It shall be health to thy navel,.... That part of the body which is the knot of the intestines; and may be put for the bowels and inward parts, which being sound, the body is in health; and these may be put for the whole body: and so the Septuagint version renders it, "to thy body"; and this may be put for the whole person.

Jamieson-Fausset-Brown Reformed @jfbcommentary

It--This conduct. health--(Compare Margin). to thy navel--for all the organs of nourishment. marrow--(Compare Margin). bones--frame of body. True piety promotes bodily health.