classic waka stream

散りぬればくやしきものを大井川
岸の山吹今日さかりなり
Roma-ji

Chirinureba kuyashiki mono o Ōigawa kishi no yamabuki kyō sakari nari

English Translation
Once they have scattered
it will be too late to mind —
and on the Ōi's
bank the yellow roses are
at their height, and that is today
Meaning
Once they have scattered it will be too late to mind — and the yellow roses on the bank of the Ōi are at their height today.
Commentary
100 The Yellow Roses on the Bank

While the Lesser Captain Fujiwara no Suenawa was living at Ōi, the emperor had said he would come when the flowers were at their best; and as he appeared to have forgotten entirely, Suenawa composed this poem. The emperor, moved by it, came in haste. The section closes on that sentence.
Fujiwara no Suenawa held the rank of Lesser Captain and was the father of the Ukon who appears in the eighty-first through eighty-fifth sections. Ōi is a place in Yamashiro province, on the Ōi river.
The setting is his house at Ōi, with the yellow roses at their height.
What prompted the poem was that the emperor, having said he would come for the flowers, seemed to have forgotten.
Moved by it, he came in haste. A single poem moves a man, following on from the ninety-ninth section, where a poem produced an imperial progress.

The opening says that once they have scattered it will be too late to regret it, its concessive particle carrying that regret in advance. He is urging haste before the fall.
The yellow roses on the bank of the Ōi are a flower long associated in poetry with water's edge.
The closing states flatly that today is the height of them. The word for today says that if he is coming, it must be now.
For a poem of urging, it neither asks him to come nor accuses him of forgetting; it reports the state of the flowers and leaves the decision to him. That the emperor came at once is the measure of it. Where the ninety-ninth section asked the leaves to wait, this one tells a man to hurry, and the two make a pair.
Source
Yamato Monogatari
Other