classic waka stream

So at last I have
turned my back upon the world
and left it behind—
that I did not cast it off
sooner is what I regret

Meaning
So in the end I have turned from the world altogether. What I regret is not having cast it off sooner.
Commentary
Volume Two: Yasuyori's Prayer

 The three men exiled to Kikai-ga-shima—Shunkan, superintendent of Hosshō-ji; Taira no Yasuyori; and the Tanba Lesser Captain Naritsune—stayed alive only because Naritsune's father-in-law Norimori kept sending clothing and food from his estate at Kase in Hizen. Their lives hung like dew on a blade of grass; it was less that they clung to them than that they simply went on.
 Yasuyori had long meant to take vows. On the journey into exile, at Murozumi in Suō, he shaved his head and took the name Shōshō. It was what he had wanted all along, and this is the poem he composed then.
 Afterward he and Naritsune proposed to install the three Kumano deities on the island. Shunkan, an unbeliever by nature, would have nothing to do with it. The two walked the island looking for ground that resembled Kumano, named a place where a waterfall thundered the Nachi Mountain, decided that this peak was Hongū and that one Shingū, and each day went through the motions of a Kumano pilgrimage, praying to be allowed home. Having no clean robes to change into they wore hemp, bathed in a marsh pool and called it the pure water of the Iwada River, climbed to high ground and took it for the Hosshin Gate. With no paper for offerings, they broke off flowers, and Yasuyori spoke the prayer.

 "Turned my back and left it behind" means to have taken vows and given up the world entirely. The completive force of hatsu is strong: he has gone past the point of return.
 The lower verse is the heart of it. What he regrets is not having taken vows, but having taken them too late. Had he left the world sooner, he would not be standing here as an exile. Read against the island around him, the verse carries weight. Taking vows is at once the fulfillment of a wish and a regret arriving too late.
 The Tale of the Heike stages many renunciations, but this is the earliest attended by a poem. The same subject returns, in altered form, in Koremori's renunciation in Volume Ten and in the Kenreimon-in chapters at the close.

somukihatsu……to turn from the world entirely by taking vows.
toku……early, soon.
sutezarishi……did not cast off.
kuyashiki……is a thing regretted.
Shōshō……Yasuyori's name in religion.
Kikai-ga-shima……an island of exile said to lie off Satsuma.
Murozumi……a port in Suō, in present-day Hikari, Yamaguchi.
kanjō……to invite and enshrine a divided spirit of a deity.
jōe……the white robe worn on pilgrimage.
Hosshinmon……the great gate of Kumano Hongū.
Source
Heike Monogatari
Other