Psalm 26

"I will wash mine hands in innocency: so will I compass thine altar" describes two visible acts. Israel's law prescribed a hand-washing rite when a body was found in open country and no killer could be identified: the elders of the nearest town washed their hands over a sacrificed heifer and declared publicly that their hands had not shed this blood. Washing hands was a legal statement anyone watching could read.

Priests also washed at a bronze basin before serving at the altar, and the psalm's "compass thine altar" pictures a worshiper moving around the altar in procession while telling aloud what God has done — the standard shape of a thanksgiving offering, which included a public recitation.

"Examine me, O Lord, and prove me; try my reins and my heart" uses metal-testing words again — assay me. The reins are the kidneys, which Hebrew thought treated as the seat of the deepest impulses, the part of a person no one else can inspect.

The list of company he has refused — vain persons, dissemblers, evildoers, the wicked, bloody men whose right hand is full of bribes — is a courtroom list. A bribe in the right hand is the picture of justice bought at the gate, which the Law names repeatedly because it was the standard way the powerful won.