This is an Old Testament promise of bodily healing based upon the character of Yahweh as the Healer. It is clear that the dimension of healing promised here is specifically to include physical wholeness. The text reinforces the healing covenant, since the Hebrew word translated “diseases” is from the same root as the word for “disease” in Exodus 15:26.
Further, the words for “heal” are the same in both passages, the distinct meaning involving the idea of mending or curing. The two texts form a strong bond and bear witness from the Old Testament that the Lord not only forgives iniquities, but heals our diseases.
If under the former covenant bodily healing was pointedly included with the Father’s many other benefits, we can rejoice and rest in faith. The new covenant “glory” exceeds everything of the old (2 Cor. 3:7–11), and we can be certain that God, in Christ, has made a complete provision for the well-being of our total person.
