Symbolism, Imagery, Allegory
There are a few references to swords throughout the story, and we don't have to page Dr. Freud to diagnose a good heavy-handed phallic symbol when we see one.
In one memorable encounter, Pamela is absolutely terrified when Lady Davers's nephew, Jackey, draws his sword. It goes down like this: "[Lady Davers's] Kinsman set his Back against the Door, and put his Hand to his Sword, and said, I should not go, till his Aunt permitted it. He drew it half-way; and I was so terrified, that I cry'd out, Oh! the Sword! the Sword!" (92.94).
Okay, so, granted Pamela was probably afraid for her safety (even though the sword was never fully drawn), but we're thinking something else is going on here. Sometimes a sword isn't just a sword, if you know what we mean.
Pamela also makes reference to a sword when providing her first (negative) impressions of Colbrand. After painting a truly horrifying picture of Colbrand's appearance, she notes that, "As to the rest, he was drest well enough, and had a Sword on, with a nasty red Knot to it. . ." (53.19). Here, Pamela directly associates the sword with a person who has been entrusted with assisting the master in his nefarious plans, which are definitely sexual in nature.
Then, of course, there's the fact that Mr. B is renowned as "a great Master of his Sword" (93.132).
Yeah, not master enough during the first half of the book, if you ask us.