classic waka stream

Someone there must be
Who has loosed the string of gems—
White jewels scattered,
Though the sleeve that would receive
Them is far too narrow still.

Meaning
There must be someone above the waterfall who has loosened the string of white jewels, for they scatter without pause. Yet the sleeve that would catch them is too narrow, and they spill away.
Commentary
87. Even a Boxwood Comb

There was once a man who lived in the village of Ashiya in the province of Settsu (present-day Hyōgo Prefecture), because he had lands there through family connections. The man held no great rank and only loosely served at court, so deputy officers of the Imperial Guards often gathered there. The man's elder brother was also the head of the Guards, and they would wander about the seashore before the man's residence.

One day the elder brother suggested that they go to see the Nunobiki Waterfall high in the mountains, and so they climbed the mountain. The waterfall was unlike ordinary ones: the water slid down a stone surface about twenty jō (roughly sixty meters) in length and five jō (about fifteen meters) in width. Where the water struck protruding rocks along the way, it broke apart and scattered into droplets about the size of mandarins or chestnuts. Those who were present were asked to compose poems on the waterfall.

After hearing the poem composed by the elder brother, the head of the Guards—
"Waiting for the day
When my world will be my own—
Today or tomorrow—
Which rises higher, I wonder:
This fall or my tears that pour?"
—the man composed this poem in reply. When those who were present heard it, they were so taken with the poem that they stopped composing further verses.

While describing the actual sight of the water scattering, the poem also responds to the lament expressed in the elder brother’s poem about his unhappy fate. It suggests that even if he wishes to gather and console his brother’s sorrow, his own sleeve—symbolizing his low rank and limited power—is too narrow to receive and support it. Those who were present may have stopped composing because they were struck both by the clever imagery of the poem and by the feelings between the brothers.

The elder brother, the head of the Guards, was Ariwara no Yukihira, the elder brother of Ariwara no Narihira. This poem is also included in the Kokinshū as a poem by Yukihira.
Source
Ise Monogatari
Other