The facts speak for themselves.
τὰ πεπραγμένα αὐτὰ βοᾷ.
Original text (Ancient Greek)
Notes from Wikiquote
Compare Cicero, Pro Milone, 53:
res loquitur ipsa, iudices, quae semper valet plurimum.
The facts, O judges, speak for themselves; facts, which are always of the greatest weight in a cause. (tr. C. D. Yonge, 1852)