“All men shall fear, And shall declare the work of God; For they shall wisely consider His doing.” (v.9)
Psalm 64 is believed to have been written in the same context as Psalm 63, during the time of Absalom’s insurrection. It is a prayer for deliverance from cunning and malicious enemies, with a confident view of their overthrow, which will honor God, give joy to the righteous, and cause all men to fear and consider their actions.
Here in our text David is expressing that when God brings upon men the schemes they have desired on others, “all men shall fear.” They shall then perceive God's hand in it, and shall be led to declare "God's work." For they shall understand that God is on the side of the righteous, to the terrible discomfiture of the wicked.
This psalm then should remind us to be confident in God’s working to preserve us from cunning and malicious people who may be scheming behind our backs. For as with David, He will turn those schemes back upon them.
The Truth: “He frustrates the schemes of the crafty, so they achieve no success.” (Job 5:12)