Be afflicted, and mourn, and weep
Not in a bare external way; not by afflicting the body with fastings and scourgings, by renting of garments, and clothing with sackcloth, and putting ashes on the head, and other such outward methods of humiliation; but afflicting the soul is meant, an inward mourning and weeping over the plague of the heart, the impurity of nature, and the various sins of life; after a godly sort, and because contrary to a God of infinite love and grace; in an evangelical way, looking to Jesus, and being affected with the pardoning grace and love of God in Christ.
Let your laughter be turned to mourning, and your joy to heaviness;
meaning their carnal joy, on account of their friendship with the world, and their enjoyment of the things of it, since they consumed them on their lusts, and which betrayed enmity to God.