classic waka stream

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.

Meaning
Even if, in the blowing wind, last year’s cherry blossoms were not to fall at all, still the heart of a person is far more difficult to rely upon.
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 man’s reply to the woman’s poem: “Morning dew may yet remain without vanishing—such it might well be; but who in this fleeting world could rely on anyone?”

It expresses the thought that even a miracle such as cherry blossoms continuing to bloom without falling is scarcely imaginable, yet the heart of a woman is still more uncertain and cannot be trusted.
Source
Ise Monogatari
Other