Within the Commentary on Zechariah, Didymus shows himself to be a thoroughly intertextual reader of scripture. He moves from the text he is commenting on to a wide variety of other passages, quoting less frequently from the historical books which do not suit his allegorical method. Besides the gift of having a mind like a concordance, he also shows familiarity with philosophical terms and categories of the Stoics, Epicureans, and Pythagoreans (from whom, with Philo, he derives his occasional number symbolism hermeneutic). His works also seem to cite passages from the deuterocanonical books of the Old Testament as well as Barnabas, the Shepherd of Hermas and the Acts of John. According to Bart Ehrman, his canon extended to at least include Barnabas and the Shepherd. It has been suggested by R.M. Grant regarding Origen's similarly expanded canon that while he lived in Alexandria he accepted the broader tradition of the church in Alexandria, but upon moving to Caesarea and finding the books were not accepted there henceforth manifested greater reserve towards them. Why Didymus would not have inherited his teachers later hesitation is unclear. Among his peers his hermeneutical method seems to have been met with mixed reactions. Jerome, who requested his commentary and considered him a mentor, is still baffled by Didymus's use of what he considered apocryphal works. Readers such as Diodore in Antioch found his hermeneutical approach somewhat gratuitous and arbitrary. What none seem to deny, however, is that Didymus was unhindered by blindness in his remarkable ability to recall the sacred text.