classic waka stream

Having nowhere else,
she was washed up on this shore
of mine, and I took
her for a scrap of drifting weed
no fisher came to look for

Meaning
Having nowhere else to go, she was washed up on this shore of mine, and I took her for a scrap of weed that no fisher would come looking for.
Commentary
Part One: Miyuki

 Before two such formidable men Tamakazura was too abashed to answer, so Genji made this poem in her place, adding that the reproach was most unreasonable. "Quite so," said the Minister, who had nothing further to say, and withdrew beyond the blinds. Afterward the princes and young nobles who had gathered wondered why he had stayed so long inside; and only Kashiwagi and the Lesser Captain, who knew, felt both the pain and the relief of never having spoken their hearts.

 "Yorube nami" is having nowhere to turn, with "yoru" playing on waves washing in. The shore is Genji; "washed up" is his taking in the girl who drifted to him. The fisher is the Minister, and the weed is Tamakazura, whom no one troubled to seek. The poem takes over the whole marine vocabulary of the other and changes only whom the fisher stands for: it was you, he says quietly, who never came looking. Refusing to receive the reproach and returning it intact leaves the Minister with nothing to answer. Written in a daughter's place, it is in truth an exchange between two grown men.
Author
Murasaki Shikibu
Source
Genji Monogatari
Other