Psalms - Songs and prayers expressing worship, lament, and trust in God

In Psalm 43, a prayer for vindication and light, the psalmist asks God to send out His light and truth to lead him to God's holy hill and altar, so he can praise God on the lyre and overcome his soul's discouragement.

Judge me, O God, and plead my cause against an ungodly nation: O deliver me from the deceitful and unjust man.

For thou art the God of my strength: why dost thou cast me off? why go I mourning because of the oppression of the enemy?

O send out thy light and thy truth: let them lead me; let them bring me unto thy holy hill, and to thy tabernacles.

Then will I go unto the altar of God, unto God my exceeding joy: yea, upon the harp will I praise thee, O God my God.

Why art thou cast down, O my soul? and why art thou disquieted within me? hope in God: for I shall yet praise him, who is the health of my countenance, and my God.