The author of the Fifteenth Psalm is a priest charged with the responsibility of screening pilgrims who have come up out of the Dispersion bent on worshiping in the Temple. Known as "the guardian of the threshold," he is to see that no one enters the hallowed precincts unworthily. For the worship experience is not to be taken lightly. As Paul later puts it, let those entering the sanctuary not engage in

...silly talk, nor levity, which are not fitting; but instead let there be thanksgiving. (Ephesians 5:4)

Hence, before admitting the group to the Temple’s sacred halls the priest must check their religious credentials.

The practice is by no means restricted to Israel. Babylon, Egypt, and Greece, for example, protected the purity of their faiths equally diligently in similar manner. "Only…