Psalm 51, one of the penitential psalms, is the 51st psalm of the Book of Psalms, beginning in English in the King James Version: "Have mercy upon me, O God". In the slightly different numbering system used in the Greek Septuagint and Latin Vulgate translations of the Bible, this psalm is Psalm 50. In Latin, it is known as Miserere, in Ancient Greek: Ἥ Ἐλεήμων, romanized: Hḗ Eleḗmōn), especially in musical settings. The introduction in the text says that it was composed by David as a confession to God after he sinned with Bathsheba.
Latin text on a holy water font: see verse 9 below
The Book of Psalms, also known as the Psalms, or the Psalter, is the first book of the third section of the Hebrew Bible called Ketuvim ("Writings"), and a book of the Old Testament.
David composing the Psalms, Paris Psalter, 10th century
An 1880 Baxter process illustration of Psalm 23, from the Religious Tract Society's magazine The Sunday at Home
Psalm 11 in the 9th-century Utrecht Psalter, where the illustration of the text is often literal.
David Playing the Harp by Jan de Bray, 1670