Ὡς δὲ ἐγέννησε Θέτις ἐκ Πηλέως βρέφος, ἀθάνατον θέλουσα ποιῆσαι τοῦτο, κρύφα Πηλέως εἰς τὸ πῦρ ἐγκρύβουσα τῆς νυκτὸς ἔφθειρεν ὃ ἦν αὐτῷ θνητὸν πατρῷον, μεθ’ ἡμέραν δὲ ἔχριεν ἀμβροσίᾳ. Πηλεὺς δὲ ἐπιτηρήσας καὶ σπαίροντα τὸν παῖδα ἰδὼν ἐπὶ τοῦ πυρὸς ἐβόησε· καὶ Θέτις κωλυθεῖσα τὴν προαίρεσιν τελειῶσαι, νήπιον τὸν παῖδα ἀπολιποῦσα πρὸς Νηρηίδας ᾤχετο. κομίζει δὲ τὸν παῖδα πρὸς Χείρωνα Πηλεύς. ὁ δὲ λαβὼν αὐτὸν ἔτρεφε σπλάγχνοις λεόντων καὶ συῶν ἀγρίων καὶ ἄρκτων μυελοῖς, καὶ ὠνόμασεν Ἀχιλλέα (πρότερον δὲ ἦν ὄνομα αὐτῷ Λιγύρων) ὅτι τὰ χείλη μαστοῖς οὐ προσήνεγκε.
(Apollodorus, Bibl. 3.13.6)
When Thetis had got a babe by Peleus, she wished to make it immortal, and unknown to Peleus she used to hide it in the fire by night in order to destroy the mortal element which the child inherited from its father, but by day she anointed him with ambrosia. But Peleus watched her, and, seeing the child writhing on the fire, he cried out; and Thetis, thus prevented from accomplishing her purpose, forsook her infant son and departed to the Nereids. Peleus brought the child to Chiron, who received him and fed him on the inwards of lions and wild swine and the marrows of bears, and named him Achilles, because he had not put his lips to the breast; but before that time his name was Ligyron. (tr. James George Frazer)