That was actually a fairly embarrassing topic for the angel. He once gave away the sword, and once had it more or less taken from him. His faith in the ineffable plan was all that prevented him from actually feeling offended by it. The sword was far safer where it was, rather than in the hands of mortals. Or worse. Castiel's obvious sarcasm and disbelief did nothing for the Principality's confidence, however. But Aziraphale was not about to be taunted into making a rash comeback.
"It is in a safe place." It wasn't a lie. He might not know its current exact whereabouts but he knew those who sent the delivery man were on the right side, and safely tucking that and the other artifacts the Horsemen had wielded away. "Shame I don't have it with me, or I would happily show it to you. It is really quite an impressive piece. But it isn't the sort of thing once carries with them everywhere they go."
Aziraphale eyed his companion, realizing he was suddenly the one being put on the spot. Castiel was quick to question him, but had not offered any information of his own.
"So, I don't believe I caught your rank?" There was a reason Crowley had once told him he was enough of a bastard for Crowley to like him.