classic waka stream

行く水に数かくよりもはかなきは
思はぬ人を思ふなりけり
Roma-ji

Yuku mizu ni kazu kaku yori mo hakanaki wa
omowanu hito o omou narikeri

English Translation
More fleeting even
Than to trace a count in
Water flowing on—
Is to love a person who
Does not think of one at all.
Meaning
More fleeting even than tracing numbers upon flowing water is to love a person who does not think of one at all.
Commentary
50. If Birds’ Eggs Were Piled

There was a certain man. He resented a woman who reproached him, saying that he was unfaithful.
The man and woman composed poems, each blaming the other.
This poem is the woman’s reply to the man’s poem: “Though in the blowing wind last year’s cherry blossoms should not fall at all—ah, how hard to rely on the heart of a person.”
From reproaching each other’s inconstancy, the exchange turns to lamenting the helpless sorrow of unrequited love.

To trace a count upon flowing water—writing one, two, three upon its surface—is a metaphor for something fleeting; this expression appears also in the Nirvana Sutra, and thus may be seen as an ancient comparison.
Source
Ise Monogatari
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