Plutarch, De Iside et Osiride 5

οἱ δʼ ἱερεῖς οὕτω δυσχεραίνουσι τὴν τῶν περιττωμάτων φύσιν, ὥστε μὴ μόνον παραιτεῖσθαι τῶν ὀσπρίων τὰ πολλὰ καὶ τῶν κρεῶν τὰ μήλεια καὶ ὕεια, πολλὴν ποιοῦντα περίττωσιν, ἀλλὰ καὶ τοὺς ἅλας τῶν σιτίων ἐν ταῖς ἁγνείαις ἀφαιρεῖν, ἄλλας τε πλείονας αἰτίας ἔχοντας καὶ τὸ ποτικωτέρους καὶ βρωτικωτέρους ποιεῖν ἐπιθήγοντας τὴν ὄρεξιν. τὸ γάρ, ὡς Ἀρισταγόρας ἔλεγε, διὰ τὸ πηγνυμένοις πολλὰ τῶν μικρῶν ζῴων ἐναποθνήσκειν ἁλισκόμενα μὴ καθαροὺς λογίζεσθαι τοὺς ἅλας εὔηθές ἐστι. λέγονται δὲ καὶ τὸν Ἆπιν ἐκ φρέατος ἰδίου ποτίζειν, τοῦ δὲ Νείλου παντάπασιν ἀπείργειν, οὐ μιαρὸν ἡγούμενοι τὸ ὕδωρ διὰ τὸν κροκόδειλον, ὡς ἔνιοι νομίζουσιν οὐδὲν γὰρ οὕτω τίμιον Αἰγυπτίοις, ὡς ὁ Νεῖλος ἀλλὰ πιαίνειν δοκεῖ καὶ μάλιστα πολυσαρκίαν ποιεῖν τὸ Νειλῷον ὕδωρ πινόμενον. οὐ βούλονται δὲ τὸν Ἆπιν οὕτως ἔχειν οὐδʼ ἑαυτούς, ἀλλʼ εὐσταλῆ καὶ κοῦφα ταῖς ψυχαῖς περικεῖσθαι τὰ σώματα καὶ μὴ πιέζειν μηδὲ καταθλίβειν ἰσχύοντι τῷ θνητῷ καὶ βαρύνοντι τὸ θεῖον.

The priests feel such repugnance for things that are of a superfluous nature that they not only eschew most legumes, as well as mutton and pork, which leave a large residuum, but they also use no salt with their food during their periods of holy living. For this they have various other reasons, but in particular the fact that salt, by sharpening the appetite, makes them more inclined to drinking and eating. To consider salt impure, because, as Aristagoras has said, when it is crystallizing many minute creatures are caught in it and die there, is certainly silly. It is said also that they water the Apis from a well of his own, and keep him away from the Nile altogether, not that they think the water unclean because of the crocodile, as some believe; for there is nothing which the Egyptians hold in such honour as the Nile. But the drinking of the Nile water is reputed to be fattening and to cause obesity. They do not want Apis to be in this condition, nor themselves either; but rather they desire that their bodies, the encasement of their souls, shall be well adjusted and light, and shall not oppress and straiten the divine element by the predominance and preponderance of the mortal.