ἄνω ποταμῶν ἱερῶν χωροῦσι παγαί → the springs of sacred rivers flow upward, backward to their sources flow the streams of holy rivers
as the saying goes: use P. τὸ λεγόμενον, V. ὡς λόγος.
confessedly: P. ὁμολογουμένως.