φησὶν σιωπῶν
From LSJ
οὗτος ἐγὼ ταχυτᾶτι· χεῖρες δὲ καὶ ἦτορ ἴσο → this is my speed: my hands and heart are its equal, such am I for speed; my hands and heart are just as good
Greek > English (Woodhouse)
his silence gives consent, by his silence he says yes, his silence is an admission