Such as no one
Could bleach them.”
καὶ τὰ ἱμάτια αὐτοῦ ἐγένετο στίλβοντα λευκὰ λίαν, οἷα γναφεὺς ἐπὶ τῆς γῆς οὐ δύναται οὕτως λευκᾶναι.
This description of the clothing of Jesus can be found in all 3 synoptic gospels, Matthew, chapter 17:2, Luke, chapter 9:29, and here in Mark, but there are minor differences in all 3 accounts. Jesus was transfigured in front of the 3 apostles. There was a metamorphosis, as the appearance of Jesus changed right before their very eyes. There was no mention of the face of Jesus changing, as in Matthew. Mark indicated that Jesus’ clothes or garments became a dazzling white (καὶ τὰ ἱμάτια αὐτοῦ ἐγένετο στίλβοντα λευκὰ λίαν). They were so white that not even any cleaner on earth could bleach them any whiter (οἷα γναφεὺς ἐπὶ τῆς γῆς οὐ δύναται οὕτως λευκᾶναι). Suddenly, the human Jesus seemed more brightly divine with his amazing glittering white clothes. White and light were good, while black and darkness were bad.