'Lesson' in the Bible

Later the Lord explained, "In the same way that my servant Isaiah has walked around in undergarments and barefoot for the past three years, as an object lesson and omen pertaining to Egypt and Cush,

Therefore He poured out on Israel the heat of His angerAnd the fierceness of battle;And engulfed him in fire,Yet he did not recognize [the lesson of repentance which the Assyrian conquest was intended to teach];It burned him, but he did not take it to heart.