A.T. Robertson Commentary Matthew 17:8

"And lifting up their eyes, they saw no one, save Jesus only." — Matthew 17:8 (ASV)

Lifting up their eyes (επαραντες τους οφθαλμους αυτων). After the reassuring touch of Jesus and his words of cheer.

Jesus only (Ιησουν μονον). Moses and Elijah were gone in the bright cloud.