53:3 none that doeth good. Compare Psalm 14, which is practically the same as Psalm 53.
Psalm 54 (title) Maschil. The superscript indicates this to be a maschil psalm, and that David wrote it as a result of the inhospitable treatment he received by the inhabitants of Ziph, south of Israel, as he was fleeing from Saul (I Samuel 23:19-24; 26:1-2). It is both a prayer for help against those who persecute believers and a testimony of confidence that God will indeed deliver them.