"I have a gift for you," Master Palaemon said. "Considering your youth and strength, I don't believe you will find it too heavy."
"I am deserving of no gifts."
"That is so. But you must recall, Severian, that when a gift is deserved, it is not a gift but a payment. The only true gifts are such as you now receive. I cannot forgive you for what you have done, but I cannot forget what you were.
The first time I read this, I thought it was a good definition of a gift. And it is. But I see now that it's also a reference to divine grace. I was going to say something about it, but it seems like its exact nature is a point of contention between different sects of Christianity, and it raises the issues of original sin and free will. So I'm going to weasel out of this and say I'll talk about it "later" when it comes up again in the book.
I shall not bore you with a catalog of her virtues and beauties; you would have to see her and hold her to judge her justly. Her bitter blade was an ell in length, straight and square-pointed as such a sword's should be. Man-edge and woman-edge could part a hair to within a span of the guard, which was of thick silver with a carven head at either end. Her grip was onyx bound with silver bands, two spans long and terminated with an opal. Art had been lavished upon her; but it is the function of art to render attractive and significant those things that without it would not be so, and so art had nothing to give her. The words Terminus Est had been engraved upon her blade in curious and beautiful letters, and I had learned enough of ancient languages since leaving the Atrium of Time to know that they meant This Is the Line of Division....
"There is a channel in the spine of her blade, and in it runs a river of hydrargyrum - a metal heavier than iron, though it flows like water. Thus the balance is shifted toward the hands when the blade is high, but to the tip when it falls.
What's an epic hero without a magic sword? OK, maybe not magic, but certainly impressive. The description suggests that it's about five and a half feet long. The square tip and engraved motto are characteristic of executioner's swords, but I couldn't find any references that talked about real executioner's swords with a man-edge and woman-edge or a mercury (hydrargyrum) core. If you find one, let me know. Terminus is a Latin word that means boundary, limit, end, or border. Wolfe loosely translates this for the purpose of a little black humor - the sword is a line of steel that divides people's heads from their bodies. An alternative translation is "This Is the End," which is appropriately intimidating. Either meaning is fit for a weapon of death, since death is a border or an end (or both), depending on what you believe.
Terminus is also the name of the Roman god of boundaries. During his annual festival, people sanctified their boundary stones, with which the god was identified. "The marker itself would be drenched in the blood of a sacrificed lamb or pig." This has an interesting parallel with the sword, which will also be blood-drenched after a "sacrifice" of sorts. "On occasion Terminus' association with Jupiter extended to regarding Terminus as an aspect of that god;" Jupiter was the Father of the Gods, and a sword is kind of shaped like a cross. The core of mercury suggests the Roman god Mercury. "Romans associated Mercury with the Germanic god Wotan," or Odin. Odin is also Father of the gods (sort of - Norse mythology isn't so straightforward), and he "hanged himself from the tree called Yggdrasill whilst pierced by his own spear in order to acquire knowledge." So he has echoes of both the Father and the Son of the Trinity. Mercury led "newly-deceased souls to the afterlife," and the sword creates newly-dead souls. "Alchemists thought of mercury as the First Matter from which all metals were formed." This First Matter is like the Hindu Brahman, which I've mentioned before. I wanted to relate mercury to the Holy Spirit, so I'd have the whole Trinity, but I couldn't. I leave it as an exercise to the reader.