Hsuan Chueh (665 – 713 CE) was a highly influential; Zen monk and teacher in south-east China. Among his works was a collection of Zen teaching poems, such as this one.

When we see truly, there is nothing at all.
There is no person; there is no Buddha.
Innumerable things of the universe
Are just bubbles on the sea.
Wise sages are all like flashes of lightning

Translation Robert Aitken