What does Psalm 12:7 mean?

Those being protected, here, are poor and oppressed people who are being abused by wicked men (Psalm 12:3–5). David trusts God to guard His people from the generation of proud, deceptive, violent people (Psalm 12:1–2).

The term "generation," as used here, can be a reference to a culture or a society. It can also refer to major attitudes or groups within a culture. In that sense, there are two main "generations" mentioned in Scripture. There is the generation of the righteous (Psalm 14:5), also called "the generation of those who seek him, who seek the face of the God of Jacob" (Psalm 24:6), "the generation of your children" (Psalm 73:15), and "the generation of the upright" (Psalm 112:2).

In sharp contrast to this righteous generation is the lying generation David mentions in this verse. The apostle Paul refers to this latter generation as "a crooked and twisted generation" (Philippians 2:15). The Lord protects His people from the generation that insults Him and persecutes His people. Jesus acknowledged in John 16:33 that believers will be persecuted, but He promised His peace and said, "Take heart; I have overcome the world." Jude 1:24–25 ascribes praise to the Lord for His protection of His people all the way to heaven.