Every calculator you've ever used balks at the same request. Type a number, hit divide, tap zero, and the screen returns an error rather than an answer. It is one of the few places where a machine built to be obedient simply refuses. Ask why, and the standard reply is that division by zero is undefined. Not infinite, not impossible in some cosmic sense, just undefined: outside the range of things the operation is allowed to mean.
It helps to remember what division actually promises. When we write twelve divided by four, we are asking a question: what number, multiplied by four, gives twelve. Division by zero asks the same kind of question in a form that has no honest answer. What number, multiplied by zero, gives twelve? None does, because anything times zero collapses to zero, always, without exception. And what number, multiplied by zero, gives zero itself? Every number does, all at once, which is just as unworkable as no answer at all. So the operation does not fail from want of an answer. It fails from too many contradictory ones, or from none, depending which zero you start with. Calling the result infinity would be a shortcut that hides this, papering over the contradiction with a symbol that behaves nothing like an actual number. Mathematicians, to their credit, prefer the discomfort of a boundary to the comfort of a fake extension.
There's an old Upanishadic image that keeps circling back to me in this territory, though I want to be careful with it. Loosely rendered, it says that from fullness, fullness comes forth, and when fullness is taken away from fullness, what remains is still fullness. Read as arithmetic, it looks like nonsense, a violation of the most basic thing subtraction is supposed to do. Take something from a whole and the whole gets smaller. That is not a rule invented by mathematicians to be difficult; it is close to the definition of what "taking away" means. So the verse is not offering a competing arithmetic. It is borrowing arithmetic's vocabulary, its confidence in subtraction and totality, and then breaking the vocabulary on purpose, to point at something that vocabulary was never built to hold. The fullness in question is not a quantity you could weigh or count, and so the ordinary promise that removal shrinks it simply does not apply. The poem knows this. Its power depends on you noticing the impossibility, not missing it.
What strikes me is how differently these two refusals work. Mathematics refuses division by zero because the refusal protects the whole structure. Every theorem, every proof by contradiction, every bit of algebra you trust rests on the operations behaving consistently, and if you let zero divide, you can prove absurd things, like one equals two, with a few lines of sleight of hand. The boundary is not squeamishness. It is the thing keeping the rest of the system honest. The Upanishadic line, on the other hand, is not protecting a system. It is deliberately stepping outside one, using a familiar operation as a springboard to gesture at something that isn't reducible to operations at all. One is a fence that keeps a structure from collapsing. The other is a fence being climbed over on purpose, for the view.
I don't think it does either tradition any favors to blur them, to say that ancient sages somehow anticipated a mathematical subtlety, or that the undefined result is secretly proof of something spiritual. The kinship is narrower and, I'd argue, more interesting than that: both are cases where a system reaches a point and says, past here, our usual rules don't produce a meaningful answer, so we will not manufacture one. What differs is what each side does with the silence. Mathematics leaves the gap open and builds carefully around its edges, using it to understand where its own logic runs out. The verse walks straight into the gap and claims it as home ground, using the very failure of ordinary subtraction as evidence that what it's describing was never the kind of thing subtraction could touch. Maybe the more useful skill, in the end, isn't choosing between these two postures. It's knowing, at any given moment, which one you're standing in.