James 4:9 - Matthew Poole's English Annotations on the Holy Bible

Be afflicted; humble yourselves for your sins, before mentioned, and in the sense of wrath approaching, if ye do not. And mourn, with inward sorrow of heart. And weep; show your inward grief by weeping, the usual expression and sign of it. Let your laughter; your carnal rejoicing in what you get by sinful courses, James 4:1,2, lusting, warring, fighting. Be turned into mourning; exchange your carnal joy for godly sorrow. And your joy; to the same purpose as laughter, before: by it he means their pleasing themselves in the success of their unrighteousness, the gain of their rapine and violence. Into heaviness; the same as mourning, or an outward expression of it in the dejection of the countenance, which usually proceeds from shame or sorrow, (and the Greek word signifies both), whereas joy and confidence make men lift up their heads or faces, Ezra 9:6 Job 10:15 Job 11:15, Job 22:26 Luke 21:28.