Praise be to the Lord, for he has heard my cry for mercy

Psalm 28:1-9
Pray and its answer
Hear my cry for mercy as I call to you for help.
Repay them for their deeds and for their evil work; repay them for what their hands have done and bring back on them what they deserve.
Praise be to the Lord,  for he has heard my cry for mercy.
The Lord is my strength and my shield; my heart trusts in him. The Lord is the strength of his people, a fortress of salvation for his anointed one.
God is his people's strength and fortress of salvation. He is not only David's God, but to all anointed men.
Danger leads to a cry for help. And a plea for the punishment of those evil people who are the source of the trouble.
Prayer turns to praise at the assurance that God has heard and answered.
Why?
Pray to the Lord for help even I am nothing, but because of God's mercy.
Pray to the Lord for help and angry to the evil one, so pray to the Lord repay them for their deeds. It is not repay them by my way but by God's way.
God is my strength, and shield: it is the power to live and protection from attack of enemy.
How?
Praise be to the Lord,  for he has heard my cry for mercy.