Nietzsche writes, in The Genealogy of Morals (Treatise I, Ch. 6):
Incidentally, people should be warned not to begin by taking these ideas of “pure” and “impure” too seriously, too broadly, or even symbolically. Instead they should understand from the start that all the ideas of ancient humanity, to a degree we can hardly imagine, are much more coarse, crude, superficial, narrow, blunt and, in particular, unsymbolic. The “pure man” is initially simply a man who washes himself, who forbids himself certain foods which produce diseases of the skin, who doesn’t sleep with the dirty women of the lower people, who has a horror of blood—no more, not much more!
When is Nietzsche dating his ancient humanity from? It seems to me, for his assertion to make sense it must be before the humanity evolved or understood the idea of the symbol. The earliest evidence we have for symbolic representation are cave paintings dating back 40 millenia ago.
(I ask this question, because Nietzsche links this characterisation of the pure man with the figure of the priest in Judaism, a jump of 30,000 years later, in pretty much the next passage).