One of the most common phrases people speak after seeing the Moby-Dick Collection is: Its all the same book right!
They are perplexed, "its the same words, so how many do you need?"
But are they the same words? Not entirely.
For a moment regard the 1967 Norton Critical Edition of Moby-Dick, as an example, nothing special about it, in fact this copy has A. Hawley signed in red pen on the inside, the cover is broken, and judging by the overall condition, A. Hawley probably never finished reading it...
His or her markings and underlinings stop at page 26, therefore he or she never made it to page 44 to read the words of the hymn read by Father Maple, and specifically un read is the first line of the second stanza: "I saw the open maw of Hell..."
Maw: The mouth, stomach, jaws, or gullet of a voracious animal, especially a carnivore.
Heck of an image, the open mouth of Hell ready to receive the offering...
Checking the 1919 Page Edition of Moby-Dick, already posted, the hymn is on page 43, and the first line of the second stanza reads: "I saw the opening maw of Hell...."
Open vs Opening. Still heck of an image. This edition carries the Copyright, 1892 Elizabeth S. Melville. So presumably this is the "official" text.
Furthermore, checking the Northwestern-Newberry Edition of Moby-Dick, page 42 has the opening line of the second stanza: "I saw the opening maw of Hell....". From the back cover: "The aim of this edition of Moby-Dick, ... is to present a text as close to the author's intention as surviving evidence permits."
Conclusion: The Norton text is in error. This may or may not be a typo, every other Norton Edition has the same wording, and in no other printed text can this wording be found.
1967 Norton Critical text
1919 Page text
1988 Northwestern- Newberry text.
Both the Norton and Northwestern edidtions were edited by Harrison Hayford.