Return, ye backsliding children,.... This is the call of the Jews to repentance in the latter day; See Gill on "Jer 3:14".and I will heal your backslidings; that is, I will forgive your sins. Sins are the diseases of the soul, and the wounds made in it; and pardoning them is healing them.
So the Targum,"I will forgive you when ye return;''see Ps 103:3, this is done by the application of the blood of Christ, the only physician, and whose blood is the balm that heals every wound; and this springs from the love of God, and his free favour to his people, even the riches of his grace and abounding mercy through Christ; and is the great motive and inducement, and what gives the greatest encouragement to return unto the Lord, Ho 14:1.