The Book of Psalms is canonical in Judaism (Ketuvim) and Christianity (Old Testament), with its authority confirmed by ancient manuscripts (Qumran), the New Testament, and councils (Hippo, Carthage). The Ethiopian Orthodox Tewahedo Church, however, has a broader canon that includes Psalm 151 as an integral part of the Psalter, accepted as Holy Scripture also by Orthodox, Syriac, and Armenian traditions, demonstrating the historical diversity of biblical canons.
Psalms
Chapter 43
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.