In this verse, David uses terms associated with intimacy and relationship. Those words reflect David's exclamation in Psalm 23:1: "The LORD is my shepherd." Because God was his personal Lord, he could find refuge in Him. It was his sincere belief that God could save him from those who were seeking to kill him. In spite of the fact that God may not choose to save him, he asks for victory with a confident faith.
Although he suffered pain, David trusted in God as his Shield and Defender. There was no doubt in his mind that the Lord was a righteous Judge who would vindicate the oppressed people. It is true that we will suffer trials and tribulations in this world and that the enemy of our soul will exploit every opportunity to depress our spirits and undermine our faith. However, he never forgot that God is in control and the oppressor's mischief will ultimately be on himself.
May we never forget, no matter what we face in this world, no matter who oppresses us, and no matter what difficult circumstances we are experiencing, that we are placing our trust in God. The Lord is the one who will vindicate all those who trust in Him, as He is the God of righteousness in whom we stand.

Dear Heavenly Father, we thank You for David's example in being pursued by his enemies, falsely accused, and persecuted for righteousness. It is in You that I hope, and You are 'the Lord my righteousness'. Thank You for promising to vindicate all Your people who are unjustly accused or are hotly pursued by the enemy of our souls. May I trust You no matter what obstacles or dangers may come my way, and I pray, like David, that my hope will be based on nothing less than the Lord Jesus Christ. 
In Jesus's name I pray. Amen.