Passage 10.24.6
ἐξελθόντι δὲ τοῦ ναοῦ καὶ τραπέντι ἐς ἀριστερὰ περίβολός ἐστι καὶ Νεοπτολέμου τοῦ Ἀχιλλέως ἐν αὐτῷ τάφος· καί οἱ κατὰ ἔτος ἐναγίζουσιν οἱ Δελφοί. ἐπαναβάντι δὲ ἀπὸ τοῦ μνήματος λίθος ἐστὶν οὐ μέγας· τούτου καὶ ἔλαιον ὁσημέραι καταχέουσι καὶ κατὰ ἑορτὴν ἑκάστην ἔρια ἐπιτιθέασι τὰ ἀργά· ἔστι δὲ καὶ δόξα ἐς αὐτὸν δοθῆναι Κρόνῳ τὸν λίθον ἀντὶ τοῦ παιδός, καὶ ὡς αὖθις ἤμεσεν αὐτὸν ὁ Κρόνος.
Upon exiting the temple and turning to the left, there is an enclosure, and within it lies the tomb of Neoptolemus, the son of Achilles; annually, the Delphians offer sacrifices to him. When one ascends from the tomb, there is a stone, not large; upon this stone they pour olive oil every day, and on each festival they place unworked wool upon it. There is also a tradition that this stone was given to Cronus instead of his child, and that Cronus later vomited it back up.