Suppose some x comes into existence at t, persists for a while, and then ceases to exist. Question is: can x ‘return’ (yu’ād) to existence, say at t’? Assume that sort of thing can happen. If so, then t would also have to return to existence alongside x, insofar as it is a part of what individuates x as x. But in that case, t and t’ would be identical; and therefore, x’s return to existence would be the same thing as its beginning of existence. But that’s clearly a contradiction. And thus, the initial assumption is necessarily false.