Walt Whitman did not write haiku, nor was he aware, to my knowledge, of Japanese haiku poetry. Still, I wish to quote a beautiful passage of his from Song of Myself, which comes from LEAVES OF GRASS. I don't feel impelled to comment on Whitman's words, as they speak for themselves, more eloquently than anything I could say.
I depart as air--I shake my white locks at the runaway sun;
I effuse my flesh in eddies, and drift it in lacy jags.
I bequeathe myself to the dirt, to grow from the grass I love;
If you want me again, look for me under your boot-soles.
You will hardly know who I am, or what I mean;
But I shall be good health to you nevertheless,
An filter and fibre your blood.
Failing to fetch me at first, keep encouraged;
Missing me one place, search another;
I stop somewhere, waiting for you.