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 13 — To the chief Musician, A Psalm of David.
How long wilt thou forget me, O LORD? for ever? how long wilt thou hide thy face from me?
How long shall I take counsel in my soul, having sorrow in my heart daily? how long shall mine enemy be exalted over me?
Consider and hear me, O LORD my God: lighten mine eyes, lest I sleep the sleep of death;
Lest mine enemy say, I have prevailed against him; and those that trouble me rejoice when I am moved.
But I have trusted in thy mercy; my heart shall rejoice in thy salvation.
I will sing unto the LORD, because he hath dealt bountifully with me.