Aki sareba oku tsuyushimo ni aezushite miyako no yama wa irozukinuramu

秋去れば置く露霜にあへずして
都の山は色づきぬらむ

Roma-ji: Aki sareba oku tsuyushimo ni aezushite miyako no yama wa irozukinuramu
English Translation: When autumn comes round
unable to withstand
the settling frost and dew,
the mountains of the capital
must have turned their colors
Meaning: Now that autumn has come, the mountains around the capital, unable to withstand the chill dew and frost, must have turned to autumn colors.
Commentary: Book Fifteen Poems of the Envoys to Silla 3699

Headnote continued from the preceding poem: "On reaching Asaji Bay in Tsushima and anchoring there, we found no fair wind and stayed five days. Gazing on the beauty of the scenery, each expressed his grief in three poems"
He imagines that the mountains of the capital, unable to withstand the autumn dew and frost, must already have turned color. With the autumn leaves of Mount Asaji in Tsushima before his eyes, his heart turns to the autumn colors of the distant mountains of the capital. Where the preceding poem thought of the distant wife by way of the moon, this one thinks of the capital by way of the autumn leaves, so the three poems at Asaji Bay are arranged to move from the scene before him to the distant capital.
According to the headnote, this is one of three poems composed when the ship anchored at Asaji Bay in Tsushima, unable to find a fair wind and staying five days, during which each gazed on the scenery and expressed his grief. Asaji Bay is thought to be Asō Bay cutting into the middle of Tsushima. The author is not named.

First line, "aki sareba": "saru" means a season's coming round: whenever autumn comes.
Second line, "oku tsuyushimo ni": "tsuyushimo" is dew and frost, or chill dew, believed to tint the leaves.
Third line, "aezushite": "au" means to withstand: unable to withstand it.
Fourth line, "miyako no yama wa": the mountains surrounding the Heijō capital, the hills of his distant home.
Fifth line, "irozukinuramu": "irozuku" means to take on autumn color, and "ramu" conjectures a present matter out of sight: they must have turned color, the poem ends.
Source: Manyoshu
Prev Poem: Amazakaru hina ni mo tsuki wa tereredomo imo zo tōku wa wakarekinikeru
Next Poem: Ashihiki no yamashita hikaru momichiba no chiri no magai wa kyō ni mo aru kamo