Deuteronomy 28:50

A nation of fierce countenance, which shall not regard the person of the old, nor shew favour to the young:

In its setting, the verse is part of the curses and covenant warnings Moses read to Israel, teaching that prosperity follows obedience to God's law and adversity follows transgression. By its words, it describes a cruel and merciless invading nation of fierce countenance that shows no respect for the old and no compassion or favor to the young. Together with Deuteronomy 26 and 27 it forms a plain and specific statement of the blessings of obedience and the curse of disobedience, expressing the principles of the law of God's kingdom so that duties are clear and minds are not left in ignorance and uncertainty.

What the chapter promises is conditional upon obedience, meaning keeping God's judgments, statutes and ordinances, walking in them and doing His word, and such obedience is for present and future good. Read with Deuteronomy 1, the chapter helps show why the Lord refused to bring the adults of the army that left Egypt into the promised land. The words are the voice of Christ from the enfolding pillar of cloud, repeated by Christ with His own voice to make duty clear and to call followers to a life of consecration and self-denial. The obligation taught has not grown weak with age but rests continually on all whom God has blessed with life, health, and temporal and spiritual advantages, with claims just as binding now and just as fresh as His gifts are fresh and continual, so those specially favored should publicly acknowledge His goodness.

As warning, the verse teaches that disobedience can bring invasion by such a fierce nation, a fearful result that stands in contrast to the blessings that come from obedience. Such evils come upon human beings because of sin, when they transgress God's law and break down the barriers He in providence erected to preserve them for health and holiness and to teach obedience, while diligent hearkening to His voice, doing right in His sight, and keeping His commandments and statutes brings His covenant of mercy that He will put none of the Egyptian diseases upon them, for He is the Lord who heals them, leading them under Christ's special direction and sheltering preservation. The prophecy was fulfilled in Israel's final overthrow and the destruction of Jerusalem and the suffering under the Roman armies that destroyed Jerusalem under Titus.