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 first book published in British North America, what has become known as the Bay Psalm Book, was the work of Richard Mather and two other ministers who transformed the Psalms into verse so they could be sung in the Massachusetts churches.