薄雲西風 Thin Cloud And West Wind
但見那：但见那：
逐句解 Line by line
And this is what they saw:
但見那 is a presentational tag introducing set-piece verse. It stands as its own unit at the close of a long prose line, so the tag alone opens the showcase.
Thin cloud broken and scattered, the west wind keen; a crane calling from far peaks, the frosted woods like brocade.
薄 takes the literary bó in verse, not the colloquial báo that pypinyin supplies. 岫 xiù is a mountain cave, by extension a peak.
The prospect all bleak and grey; the mountains long, the waters longer.
長 is cháng 'long' at both occurrences, not the zhǎng of growth that pypinyin defaults to. Both are forced positionally.
Travelling geese come down to the northern marches; the dark birds go home to the southern lanes.
塞 is sài, a frontier fortress or the frontier itself, not the sāi of stopping up. 玄鳥 is the swallow, whose southward return marks the season.
On a traveller's road one shrinks from being alone; a patched robe grows cold soon enough.
衲衣 is the mendicant's robe sewn from cast-off scraps, the standing metonym for a monk. The stanza closes on the pilgrim's exposure, which the following prose will convert from cold into its opposite.
The set-piece is a conventional autumn landscape, and its conventionality is the point: broken cloud, a keen west wind, a crane on far peaks, frost-brocaded woods, geese going north and swallows south. A reader of the period would recognise every element. The verse certifies that the season is autumn, on the authority of poetic convention rather than of any character's observation.
Only the closing couplet turns personal. 客路 — the traveller's road — and the patched robe that 'grows cold soon enough' bring the generic scene down onto the specific bodies of four pilgrims a long way from anywhere. The movement from panorama to a cold monk is the stanza's only real gesture.
Placed where it is, the verse functions as evidence. Immediately afterwards the party begins to sweat, and the reader has just been shown, in the most unimpeachable idiom available, that it ought to be freezing.