Navel - The central region of the body is taken as the representative of all the vital organs. For “health” we should read healing, or, as in the marg. There is probably a reference to the local applications used by the surgery of the period as means of healing.
Related Commentaries of Proverbs 3:8
Proverbs 3:8
8 It shall be healthc to thy navel, and marrow to thy bones.