“navel.” The Hebrew text literally reads “navel.” This is the figure of speech synecdoche, where the part, the navel, is put for the whole, the whole body. However, there seems to be a good reason God picked “navel” here. The navel is the very font of life of the body, feeding the body with everything it needed in the womb, and so it presents a good word picture here. The “navel” was the source of our well-being in the womb and also as we entered life as an independent being. In a similar way, fearing Yahweh and departing from evil is the very source of life for us in this life and will see us off to a wonderful start in our next life.
In general, fearing God and turning from evil keeps us healthy and strong mentally, emotionally, and physically. People who ignore God and get mixed up in an evil and/or bad lifestyle invariably suffer for it.
“refreshing drink.” The Hebrew text reads shiqquv (#08250 שִׁקּוּי) in the singular, and thus means, “a drink.” The “drink” is put by metonymy of effect for the effect that the drink brings, which is “refreshment,” which is why so many English versions read that way. We combined the literal with the metonymy and went with “refreshing drink,” which we feel catches both the Hebrew word and its meaning in this context.
In the biblical culture, bones that were “wet” were known to be strong, while bones that were “dry” were weak. Proverbs says a crushed or broken spirit (referring to depression), dries up the bones (Prov. 17:22; see commentary on Prov. 17:22). Job complained that the bones of the wicked were well watered (Job 21:24). See also Psalms 109:18.
The mention of both the navel, which is on the outside of the body, and the bones, which are the inner support of the body, further emphasizes that this verse is saying that fearing God and turning from evil will be healing to the whole body.