What does Psalm 17:9 mean?

The prior verse used two phrases related to God's loving care which have been widely used even outside of Scripture (Psalm 17:8). Here, David explains why he so desperately seeks God's watchful protection. Other men were seeking to harm and murder David. It's possible this psalm was written during David's persecution by king Saul (1 Samuel 20:32–33). David was surrounded by those who wanted to kill him. Only the Lord could protect him and deliver him from the enemies' ruthless hands.

Believers have always been the target of the Devil and his followers. Near the beginning of time wicked Cain killed his brother, righteous Abel (Genesis 4:8). Pharaoh tried to kill all the Hebrew male infants (Exodus 1:15–16). Haman tried to destroy Mordecai and all the Jews in the nation (Esther 3:8–11). Seeking to kill a recently-born Jesus, Herod ordered the slaughter of Jewish boys under the age of two in an entire town (Matthew 2:16). Wicked men conspired to crucify Jesus (Matthew 26:3–5; John 19:12–16). Christ's early followers suffered the wrath of unsaved Jews and Gentiles (Acts 5:40; 8:3; 16:19–24). In the tribulation, the beast and the false prophet will conduct a terrorist campaign against all who refuse the mark of the beast (Revelation 13:15–17). However, Jesus said, "Take heart; I have overcome the world (John 16:33)."