classic waka stream

たつた川もみぢみだれて流るめり
わたらば錦なかや絶えなむ
Roma-ji

Tatsutagawa momiji midarete nagarumeri wataraba nishiki naka ya taenamu

English Translation
Down the Tatsuta
the autumn leaves come scattered
and tangled, it seems —
and were I to cross, that brocade
would surely part in the middle
Meaning
Down the Tatsuta the autumn leaves come scattered and tangled; and were I to cross, that brocade would surely be broken in the middle.
Commentary
151 The Tatsuta River

The same emperor at Nara, looking at the fine autumn leaves on the Tatsuta river, heard Kakinomoto no Hitomaro compose "Tatsutagawa momijiba nagaru kannabi no Mimuro no yama ni shigure fururashi", and himself composed "Tatsutagawa momiji midarete nagarumeri wataraba nishiki naka ya taenamu". That is the whole of the section.
The emperor at Nara is the emperor of the Nara capital, who appears in the hundred and fiftieth section. Kakinomoto no Hitomaro is the great poet of the Man'yō-shū, who composes at the Sarusawa pond in that section. The Tatsuta river flows through Yamato and was famous for its autumn leaves; the sacred hill of Mimuro stands above it.
The setting is the same river.
What prompted the poem is Hitomaro's, "Tatsutagawa momijiba nagaru kannabi no Mimuro no yama ni shigure fururashi". The emperor answers it.
The section closes with this poem.

He opens from Hitomaro's own river — a properly matched reply.
What follows says the leaves come scattered and tangled, in a grammar of inference from what the eye sees.
The brocade is the leaves spread on the water, taken for figured cloth.
The closing asks whether it would part in the middle, the word meaning the centre or the midpoint. He hesitates to cross for fear of tearing the cloth. Where Hitomaro reasoned upstream, the emperor keeps his eye on the water in front of him, so that the same scene is carried in two directions.
Source
Yamato Monogatari
Other