To the point, "xylon asepton" means just "incorruptible wood".
καὶ ποιήσεις θυσιαστήριον θυμιάματος ἐκ ξύλων ἀσήπτων· καὶ ποιήσεις αὐτὸ
And thou shalt make the altar of incense of incorruptible wood. (Exodus 30:1 Brenton)
καὶ ποιήσεις σκυτάλας ἐκ ξύλων ἀσήπτων καὶ καταχρυσώσεις αὐτὰς χρυσίῳ.
And thou shalt make the staves of incorruptible wood, and shalt gild them with gold. (Exodus 30:5 Brenton)
καὶ ποιήσεις θυσιαστήριον θυμιάματος ἐκ ξύλων ἀσήπτων· καὶ ποιήσεις αὐτὸ
And thou shalt make the altar of incense of incorruptible wood. (Exodus 30:1 Brenton)
καὶ ποιήσεις σκυτάλας ἐκ ξύλων ἀσήπτων καὶ καταχρυσώσεις αὐτὰς χρυσίῳ.
And thou shalt make the staves of incorruptible wood, and shalt gild them with gold. (Exodus 30:5 Brenton)