暗自驚心 Pilgrim Is Quietly Shaken
行者聽言，暗自驚心。喝退了山神、土地，收了法身，現出本相，與八戒、沙僧道：「師父去得遠了。」八戒道：「遠便騰雲趕去。」行者听言，暗自惊心。喝退了山神、土地，收了法身，现出本相，与八戒、沙僧道：「师父去得远了。」八戒道：「远便腾云赶去。」
逐句解 Line by line
Pilgrim heard it, and privately his heart was shaken.
Eight characters, and they are the most revealing in the chapter. 暗自 means he did it where nobody could see.
He shouted the mountain god and the earth god away, gathered in his magic body, showed his true form again, and said to Bajie and Sha Monk, "Our master has gone a long way off."
喝 is hè, to shout someone off — the drinking word is a different hē entirely. 得 is the unstressed de, joining the going to how far it went. 相 is xiàng, form.
Bajie said, "If it is far, we ride the cloud and chase after him."
Nine characters of complete practicality, from the character who has been useless all chapter.
The eight characters at the start are the only moment in the chapter where Pilgrim is frightened, and the text is careful to say he hid it.
What frightens him is not the distance. He has just been told the name of the place, and a bottomless cave is not somewhere a creature who fights by hitting things can be confident of winning.
And then he dismisses the gods, drops the war shape, and reports to his brothers in nine flat characters: he has gone a long way off. Not a word about the fear. Bajie's answer — then let us fly — is the right one, and it is the first useful thing he has said since the monastery.