In this story, when and how is the narrator eventually saved?

Poe’s narrator is saved at the end, dramatically, by “an outstretched arm” that grabs him just as he is about to be forced into the pit. The story ends with a reference to “General LaSalle“ having entered Toledo; LaSalle was one of Napoleon’s generals during the Peninsular War in Spain. Poe is not a stickler for historical detail, however; in fact, it always struck me as odd why Poe would allude to LaSalle at the end of a story that clearly is about emotion, rather than historical accuracy.

The narrator is saved twice before: first, he avoids falling into the pit through luck, when he stumbles while exploring (by touch) his completely dark cell — he falls, and realizes that there is no floor where the top of his head is. Next, he’s lashed to a wooden framework and watches as a razor-sharp pendulum slowly descends to slice him open; this time rats come to his aid, and chew through the rope that binds him.