Proverbs 12:25

Here is, 1. The cause and consequence of melancholy. It is heaviness in the heart; it is a load of care, and fear, and sorrow, upon the spirits, depressing them, and disabling them to exert themselves with any vigour on what is to be done or fortitude in what is to borne; it makes them stoop, prostrates and sinks them. Those that are thus oppressed can neither do the duty nor take the comfort of any relation, condition, or conversation. Those therefore that are inclined to it should watch and pray against it. 2. The cure of it: A good word from God, applied by faith, makes it glad; such a word is that (says one of the rabbin), Cast thy burden upon the Lord, and he shall sustain thee; the good word of God, particularly the gospel, is designed to make the hearts glad that are weary and heavy-laden, Mat 11:28. Ministers are to be helpers of this joy.

— Matthew Henry's Concise Commentary (public domain)

a good word--one of comfort.

— Jamieson-Fausset-Brown Commentary (public domain)