We have been introduced earlier to the theme that Catherine Barkley has no conventional religion, and it is reiterated here in her refusal of Lieutenant Henry's invitation to enter the Milan Cathedral. The author contrasts Henry and Catherine to the soldier and his girlfriend standing together in the shelter of the church; the former have no conventional faith to protect them. Remember that the officers at the front took their refuge in houses of prostitution — obviously not an option for Henry and Catherine. What they have is their love for one another.
Henry buys a pistol to replace the one lost when he was injured. As this is the second time that our attention has been directed to Henry's pistol, we can only assume that it is an object of some importance. Notice that Henry refuses the offer of a "used, very cheap" sword. "I'm going to the front," he explains, and the proprietor of the armorer's shop replies, "Oh yes, then you won't need a sword." As Hemingway has made clear from the novel's first scene, this is not a storybook war in which combatants carry swords, much less use them: World War I is modern, unromantic, brutal. During Henry and Catherine's trip from the armorer's to the hotel near the train station, the fog that has covered the city from the start of the chapter turns to rain, the novel's symbol of death.
Staying in a hotel room for less than an entire night, with a man who is not her husband, makes Catherine feel like a whore. (The room's bordello-like décor surely doesn't help matters.) Here we are reminded of Henry's leave from the front early in the novel, which he spent for the most part in exciting but unfulfilling encounters with prostitutes, and we realize how much he has matured since.
With regard to the Hemingway style, notice that only now, after months of intimacy, does Henry learn that Catherine has a father; she learns, in turn, that he doesn't. Again, Hemingway's novels and stories are remarkable, and distinctively modern, for their lack of exposition. Though A Farewell to Arms contains almost no information about Henry's life prior to the war, much less Catherine's, we don't particularly miss it, as the present action is so compelling.
