A.T. Robertson Commentary Mark 10:22

"But his countenance fell at the saying, and he went away sorrowful: for he was one that had great possessions." — Mark 10:22 (ASV)

But his countenance fell (ο δε στυγνασας). In the LXX and Polybius once and in Mt 16:3 (passage bracketed by Westcott and Hort). The verb is from στυγνος, sombre, gloomy, like a lowering cloud. See on Mt 19:22 for discussion of "sorrowful" (λυπουμενος).