目秀眉清 Clear Brows And Fine Eyes
好大聖，捻著訣，搖身一變，變做個乾乾淨淨的小和尚兒，真個是目秀眉清，頭圓臉正；行動有斯文之氣象，開口無俗類之言辭。好大圣，捻着诀，摇身一变，变做个干干净净的小和尚儿，真个是目秀眉清，头圆脸正；行动有斯文之气象，开口无俗类之言辞。
逐句解 Line by line
Splendid Great Sage! He pinched the magic sign, gave his body a shake and turned into a spruce little monk — truly, clear of brow and fine of eye, round of head and straight of face;
好大聖 is the teller's applause line, dropped in whenever Pilgrim is about to do something worth watching. 著 is zhe, the marker of a state being held: his fingers stay pinched on the sign while everything else happens. 乾 is gān, dry, and doubled up in 乾乾淨淨 it means spick and span — not the qián of the first trigram, which is what the character hands you if you leave it alone. And 搖身一變, one shake of the body and he is something else, is still ordinary Chinese today, usually said with a sneer about somebody who has changed sides.
in his bearing the air of a scholar, in his speech not one word of the common sort.
斯文 is one of the great survivals. It starts in the 論語 as this culture of ours — the whole civilised inheritance Confucius was afraid of losing — and by the Ming it has shrunk to mean refined, genteel, well-spoken. Modern Chinese still uses it in exactly that narrowed sense. The joke is that it is being said about a monkey who has owned the face for one sentence.
The disguise is not a face. It is a class performance, and the passage builds it in that order: first the features, then the bearing, then the vocabulary. By the end Pilgrim is not merely good-looking but audibly educated, which is the part that will actually do the work.
The description runs in matched fours and eights — clear of brow, fine of eye, round of head, straight of face — and it is the same machinery the chapter used on the old man a few passages back — the old man in threes and fours and sevens, the monk in fours and eights, but the method identical. That is worth noticing. The novel has now assembled two trustworthy-looking strangers by the same procedure, and one of them is a monkey.
Which is the quiet argument underneath the comedy. If a costume can be put together this easily out of white hair, prayer beads and a good staff, then the reader has no more reason to trust the man on the slope than the demons would have to trust the little monk walking up to him.