chained_bear commented on the word mackerel-snapper I get the fish-eater thing, but I don't know why non-Catholics wouldn't want mackerel--evidenced by the use of the term in a disparaging phrase. (Or wouldn't want snapper, for that matter.)
Psalm 1 is the first of the Psalms in the Hebrew Bible. Like many of the psalms, it contrasts the  righteous  person (tzadik ×¦×××§) to the wicked or ungodly (rasha` ×¨×©×¢) or the  sinner  (chatta' ×××).
The Book of Psalms is subdivided into 5 parts. Psalm 1 is part of the first part. It has been counted as the beginning of part one in some translations, in some counted as a prologue, and in others Psalm 1 is combined with Psalm 2.