Psalm 10 is a lament over faithless, wicked, wealthy Israelites who hotly pursue the poor and the underprivileged. 

The lament - O LORD, why do you let the faithless wicked people get away with destroying the poor?  The wicked say that there is no God, that he has forgotten, that God does not see their deeds of evil, that God will not call us into account.

A plea to God (Elohim) to arise and come to the aide of the afflicted because in fact God does see the injustice and wickedness.  Break the arm of the evildoer.

Concluding confidence in God’s justice and power.   Justice has to do with conduct in relation to others. Just behavior accords with what is morally right and fair. Justice is the quality of doing what is right.  God is just and in righteousness always acts morally right and fair with people.  The wicked are not just; they do not act morally right or fair with the poor and other disadvantaged people.  We can pray in faith according to Psalm 10 that God will do justice, do the right thing, in regard to those who cannot defend themselves.