Plutarch, De Iside et Osiride 63 (part 1)

ἐμφαίνει καὶ τὸ σεῖστρον, ὅτι σείεσθαι δεῖ τὰ ὄντα καὶ μηδέποτε παύεσθαι φορᾶς, ἀλλʼ οἷον ἐξεγείρεσθαι καὶ κλονεῖσθαι καταδαρθάνοντα καὶ μαραινόμενα. τὸν γὰρ Τυφῶνά φασι τοῖς σείστροις ἀποτρέπειν καὶ ἀποκρούεσθαι, δηλοῦντες, ὅτι τῆς φθορᾶς συνδεούσης καὶ ἱστάσης, αὖθις ἀναλύει τὴν φύσιν καὶ ἀνίστησι διὰ τῆς κινήσεως ἡ γένεσις. τοῦ δὲ σείστρου περιφεροῦς ἄνωθεν ὄντος, ἡ ἁψὶς περιέχει τὰ σειόμενα τέτταρα. καὶ γὰρ ἡ γεννωμένη καὶ φθειρομένη μοῖρα τοῦ κόσμου περιέχεται μὲν ὑπὸ τῆς σεληνιακῆς σφαίρας, κινεῖται δʼ ἐν αὐτῇ πάντα καὶ μεταβάλλεται διὰ τῶν τεττάρων στοιχείων, πυρὸς καὶ γῆς καὶ ὕδατος καὶ ἀέρος. τῇ δʼ ἁψῖδι. τοῦ σείστρου κατὰ κορυφὴν ἐντορεύουσιν αἴλουρον ἀνθρώπου πρόσωπον ἔχοντα, κάτω δʼ ὑπὸ τὰ σειόμενα πῆ μὲν Ἴσιδος πῆ δὲ Νέφθυος πρόσωπον, αἰνιττόμενοι τοῖς μὲν προσώποις γένεσιν καὶ τελευτὴν αὗται γάρ εἰσι τῶν στοιχείων μεταβολαὶ καὶ κινήσεις, τῷ δʼ αἰλούρῳ τὴν σελήνην διὰ τὸ ποικίλον καὶ νυκτουργὸν καὶ γόνιμον τοῦ θηρίου. λέγεται γὰρ ἓν τίκτειν, εἶτα δύο καὶ τρία καὶ τέσσαρα καὶ πέντε· καὶ καθʼ ἓν οὕτως ἄχρι τῶν ἑπτὰ προστίθησιν, ὥστʼ ὀκτὼ καὶ εἴκοσι τὰ πάντα τίκτειν, ὅσα καὶ τῆς σελήνης φῶτʼ ἔστιν. τοῦτο μὲν οὖν ἴσως μυθωδέστερον· αἱ δʼ ἐν τοῖς ὄμμασιν αὐτοῦ κόραι πληροῦσθαι μὲν καὶ πλατύνεσθαι δοκοῦσιν ἐν πανσελήνῳ, λεπτύνεσθαι δὲ καὶ μαραυγεῖν ἐν ταῖς μειώσεσι τοῦ ἄστρου.

The sistrum (rattle) also makes it clear that all things in existence need to be shaken, or rattled about, and never to cease from motion but, as it were, to be waked up and agitated when they grow drowsy and torpid. They say that they avert and repel Typhon by means of the sistrums, indicating thereby that when destruction constricts and checks Nature, generation releases and arouses it by means of motion. The upper part of the sistrum is circular and its circumference contains the four things that are shaken; for that part of the world which undergoes reproduction and destruction is contained underneath the orb of the moon, and all things in it are subjected to motion and to change through the four elements: fire, earth, water, and air. At the top of the circumference of the sistrum they construct the figure of a cat with a human face, and at the bottom, below the things that are shaken, the face of Isis on one side, and on the other the face of Nephthys. By these faces they symbolize birth and death, for these are the changes and movements of the elements; and by the cat they symbolize the moon because of the varied colouring, nocturnal activity, and fecundity of the animal. For the cat is said to bring forth first one, then two and three and four and five, thus increasing the number by one until she reaches seven, so that she brings forth in all twenty-eight, the number also of the moon’s illuminations. Perhaps, however, this may seem somewhat mythical. But the pupils in the eye of the cat appear to growr large and round at the time of full moon, and to become thin and …