The Pequod pulls up alongside the Jeroboam, and Stubb notices that there is a crew member on that ship named Gabriel, whose exploits were spoken of during the gam with the Town-Ho (although this was not mentioned in the Town-Ho chapter). Gabriel, a “Shaker” (or radical Christian) from Nantucket, was a loud and boisterous preacher on land, and once he shipped out on the Jeroboam, he became a religious fanatic and a prophet, warning sailors about the terrible end they would meet if they encountered the White Whale. Mayhew, captain of the Jeroboam, did not listen to Gabriel, nor did Macey, the mate, but others of the crew took to Gabriel’s advice and considered him a true man of God. Gabriel announced that Moby Dick was the Shaker God itself, and that no one ought to kill it.
The Shakers were a Protestant religious sect of some influence in the 1800s. Ishmael seems especially interested in the branches of Protestant devotion that place special emphasis on man’s fate and destiny—what the Calvinists, a sect of Protestants, would call man’s “predestined fate.” Gabriel, another of the novel’s prophets, argues that Moby Dick is a God, and that to fight Moby Dick is to attempt to wrestle with God himself. Gabriel (which is also the name of one of God’s archangels, in the Bible) argues that it is immoral even to consider challenging God in this way. While Mapple swathe story of Jonah as a tale that demanded sailors to follow their captains, Gabriel is making a similar argument about Moby Dick's status in regard to men (and to Ahab). So Gabriel sees Moby Dick as a god who must not be faced. Ahab sees Moby Dick as a force that must be faced. And others, later, will argue that Moby Dick is just a big white whale. Interpretations abound.
As if to demonstrate this, Moby Dick was then spotted off the Jeroboam’s side, and a team was mounted to hunt it. But just as this was begun, the whale leapt into the air, knocked Macey from the deck, and caused him to drown. Although Mayhew considered this to be pure luck, others in the crew took Gabriel for a real prophet, and blamed Macey’s death on Mayhew’s unwillingness to believe that Moby Dick was a God.
Gabriel’s prophecy, like many of the others in the novel, comes to pass—Mayhew, like Radney before him, is killed by Moby Dick. Moby Dick’s vengeance, like God’s, is swift, decisive, and dramatic. But is this because Gabriel is right and Moby Dick has some kind of supernatural power, or because Moby Dick happens to be a particularly big and powerful whale?
Ahab hears this story from Mayhew and Gabriel during a gam between the two boats, but states that he will still seek out Moby Dick (over Gabriel’s loud objections). Starbuck finds a letter among the Pequod's sack for Macey, the dead mate, and hands it to the crew of the Jeroboam, but Gabriel throws it back to the Pequod, saying that this letter ought not to be read, for to do so would be a blasphemous business—because Macey has died. At this, the Jeroboam shifts away from the Pequod, and the sailors of the Pequod remark on the strangeness of this gam for some time afterward.
Melville appears to have a preoccupation with a certain form of “dead letter,” or a piece of mail that is not delivered to its intended recipient, and instead is lost in transit. Here, the letter for Macey cannot be given to Macey, because the man himself is dead. Melville’s other great depiction of “dead letters” comes in his story “Bartleby, the Scrivener,” in which the title character is reported to work in mail office devoted to storing undelivered mail, in New York City. Gabriel is here arguing that in dying Macey has entered the unknown, and that the unknown must not be pierced.