The Marriage to Gomer
According to the Book of Hosea, God commanded the prophet to marry Gomer, daughter of Diblaim, an unfaithful woman. The marriage was made a living sign of Israel's own unfaithfulness to the Lord, and their children were given names that carried the prophetic message: Lo-ruhamah ('not pitied'), signifying God's displeasure at Israel's idolatry, and Lo-ammi ('not my people'), representing the severing of the covenant bond.
The point of the sign lay in its reversal: just as Hosea kept covenant with his wayward wife, so God refused to abandon Israel despite its turning to false gods. The book is thus at once a prophecy of doom and a proclamation of God's enduring love for a sinful people, ending in promises of reconciliation and restoration.