Crossword puzzle clue "puzzle with number squares"

Daily crosswords, to puzzle pros (so-called from the number of squares per side)

Puzzle with number squares

Number of mispelled words in this puzzle's clues (oh, by the way, watch out for those tricky circled squares!)

Psalm 100 excerpt suggested by six puzzle answers and graphically represented by certain black squares in this puzzle

Poet whose classic work is hidden in this puzzle (see the circled squares of the completed the puzzle)

The squares of "three squares"

Number of times this puzzle's theme word appears diagonally in the grid (to complete the puzzle, shade those words plus the Down answers that begin where they meet)

Puzzle-within-a-puzzle puzzle