“Water is the beginning and the end of everything.”
[οὕτος ἔφη] ἀρχὴν τοῦ παντὸς εἶναι καὶ τέλος τὸ ὕδωρ
So, we don’t really have anything by Thales, but this summary comes from the aspirationally named Refutation of all Heresies.
ΕΥΔΟΞΑ ΑΓΝΩΣΤΑ ΚΑΤΑΓΕΛΑΣΤΑ
Apparently MST3K’s legendary “Water: the source of all bad movies” was just paraphrasing this. Who knew.
Ah! All water comes from Greece!
Everything does, right?