Charles Spurgeon Commentary Job 33:2

"Behold now, I have opened my mouth; My tongue hath spoken in my mouth." — Job 33:2 (ASV)

That is to say, "I speak with much solemnity, not as one who chatters without sense, or without due consideration, but I have opened my mouth deliberately, as one who has something to say; and I speak with my best powers of speech, as one who wishes to persuade those who hear him."