Whosever shall exalt himself shall be abased ( ταπεινωθη ìσεται, shall be humbled); and he that shall humble ( ταπεινω ìσει) himself shall be exalted. It is not clear why the rendering of the verb is not uniform in this verse.
The antithesis certainly requires it. The gnome, so often repeated (see references), seems to be, as it has been called, "an axiom in the kingdom of God." It is indeed a universal law in God's dealings with men.
Olshausen quotes a saying! of Hillel to the same purport, "My humility is my exaltation, and my exaltation is my humility." The first clause was prophetic of the speedy overthrow of the haughty Pharisees; the second is grandly illustrated in the example of Christ, who humbled himself to the death of the cross, and is now highly exalted; who "for the joy that was set before him, endured the cross, despising shame, and hath sat down at the right hand of the throne of God" (Hebrews 12:2).
St. Peter draws the lesson, "Humble yourselves under the mighty hand of God, that he may exalt you in due time" (1 Peter 5:5, 1 Peter 5:6).