From a book in Google Play,
https://play.google.com/store/books/det ... AAJ&rdot=1
p.36
the third sentence
ei de symboliko^s legetai tauta, to^n ekeinou dynameo^n onta symbola, te^n herme^neian to^n symbolo^n eipato^san
I'm unsure about the "eipato^san".
The meaning could be "let them say", guessing from the probable meaning of this sentence.
"eipon" has its imperative 3sg. "eipato^".
But 3pl. would not be "eipato^san", according to the table of conjugation for aor.2.
There is the form ending with "to^san" in perfect imperative 3pl..
But I don't know the Perfect of this verb.