So to say (ως επος ειπειν). An old idiom, here only in the N.T., common in Philo, used to limit a startling statement, an infinitive for conceived result with ως.

Hath paid tithes (δεδεκατωτα). Perfect passive indicative of δεκατοω, "has been tithed." This could only be true of Levi "so to speak."