Plutarch, De Iside et Osiride 39 (part 1)

ἡ δὲ Τυφῶνος ἐπιβουλὴ καὶ τυραννὶς αὐχμοῦ δύναμις ἦν ἐπικρατήσαντος καὶ διαφορήσαντος τήν τε γεννῶσαν ὑγρότητα τὸν Νεῖλον καὶ αὔξουσαν. ἡ δὲ συνεργὸς αὐτοῦ βασιλὶς Αἰθιόπων αἰνίττεται πνοὰς νοτίους ἐξ Αἰθιοπίας· ὅταν γὰρ αὗται τῶν ἐτησίων ἐπικρατήσωσι τὰ νέφη πρὸς τὴν Αἰθιοπίαν ἐλαυνόντων, καὶ κωλύσωσι τοὺς τὸν Νεῖλον αὔξοντας ὄμβρους καταρραγῆναι, κατέχων ὁ Τυφὼν ἐπιφλέγει, καὶ τότε κρατήσας παντάπασι τὸν Νεῖλον εἰς ἑαυτὸν ὑπʼ ἀσθενείας συσταλέντα καὶ ῥυέντα κοῖλον καὶ ταπεινὸν ἐξέωσεν εἰς τὴν θάλασσαν. ἡ γὰρ λεγομένη κάθειρξις εἰς τὴν σορὸν Ὀσίριδος οὐδὲν ἔοικεν ἀλλʼ ἢ κρύψιν ὕδατος καὶ ἀφανισμὸν αἰνίττεσθαι· διὸ μηνὸς Ἀθὺρ ἀφανισθῆναι τὸν Ὄσιριν λέγουσιν, ὅτε τῶν ἐτησίων ἀπολειπόντων παντάπασιν ὁ μὲν Νεῖλος ὑπονοστεῖ, γυμνοῦται δʼ ἡ χώρα· μηκυνομένης δὲ τῆς νυκτός, αὔξεται τὸ σκότος, ἡ δὲ τοῦ φωτὸς μαραίνεται καὶ κρατεῖται δύναμις, οἱ ἱερεῖς ἄλλα τε δρῶσι σκυθρωπὰ καὶ βοῦν διάχρυσον ἱματίῳ μέλανι βυσσίνῳ περιβάλλοντες ἐπὶ πένθει τῆς θεοῦ δεικνύουσι (βοῦν γὰρ Ἴσιδος εἰκόνα καὶ γῆν νομίζουσιν) ἐπὶ τέσσαρας ἡμέρας ἀπὸ τῆς ἑβδόμης ἐπὶ δέκα ἑξῆς. καὶ γὰρ τὰ πενθούμενα τέσσαρα, πρῶτον μὲν ὁ Νεῖλος ἀπολείπων καὶ ὑπονοστῶν, δεύτερον δὲ τὰ βόρεια πνεύματα κατασβεννύμενα κομιδῇ τῶν νοτίων ἐπικρατούντων, τρίτον δὲ τὸ τὴν ἡμέραν ἐλάττονα γίγνεσθαι τῆς νυκτός, ἐπὶ πᾶσι δʼ ἡ τῆς γῆς ἀπογύμνωσις ἅμα τῇ τῶν φυτῶν ψιλότητι τηνικαῦτα φυλλορροούντων.

The insidious scheming and usurpation of Typhon, then, is the power of drought, which gains control and dissipates the moisture which is the source of the Nile and of its rising; and his coadjutor, the Queen of the Ethiopians, signifies allegorically the south winds from Ethiopia; for whenever these gain the upper hand over the northerly or Etesian winds which drive the clouds towards Ethiopia, and when they prevent the falling of the rains which cause the rising of the Nile, then Typhon, being in possession, blazes with scorching heat; and having gained complete mastery, he forces the Nile in retreat to draw back its waters for weakness, and, flowing at the bottom of its almost empty channel, to proceed to the sea. The story told of the shutting up of Osiris in the chest seems to mean nothing else than the vanishing and disappearance of water. Consequently they say that the disappearance of Osiris occurred in the month of Athyr, at the time when, owing to the complete cessation of the Etesian winds, the Nile recedes to its low level and the land becomes denuded. As the nights grow longer, the darkness increases, and the potency of the light is abated and subdued. Then among the gloomy rites which the priests perform, they shroud the gilded image of a cow with a black linen vestment, and display her as a sign of mourning for the goddess, inasmuch as they regard both the cow and the earth as the image of Isis; and this is kept up for four days consecutively, beginning with the seventeenth of the month. The things mourned for are four in number: first, the departure and …