Letter 22: Procopius makes Diodorus the messenger who should restart letters with John.

Let the most learned Diodorus end the silence between us. He will ask you to write, and he will give you what comes from me. He is my friend; even before seeing you, he had already become your admirer, for my accounts of you created affection before sight could do so. The man loves what is noble and searches out good people, as though afraid that anyone of that kind might escape his notice. Why should I tell you more about him? Once you know him by experience, you will think my praise too small and call me a weak rhetorician, unable even to say what belongs to the case.

Ἰωάννηι Ὁ λογιώτατος Διόδωρος λύσις ἡμῖν ἔστω τῆς πρὸς ἀλλήλους σιγῆς, καὶ σὲ γράφειν ἀπαιτῶν καὶ τὰ παρ' ἡμῶν σοι διδούς. φίλος μὲν γὰρ οὗτος ἐμός, ἤδη δὲ πρὶν ἰδεῖν καὶ σὸς ἐτύγχανεν ἐραστής· οἱ γὰρ ἐξ ἡμῶν λόγοι τὰ περὶ σοῦ διηγούμενοι καὶ πρὸ τῆς θέας ἐποίουν τὸν ἔρωτα. ὁ γὰρ ἀνὴρ ἐρωτικός ἐστι τῶν καλῶν καὶ πολυπραγμονεῖ τοὺς χρηστούς, ὥσπερ δεδιὼς μή ποτέ τις τοιοῦτος ὢν διαλάθῃ. καὶ τί σοι τὰ περὶ τούτου λέγειν με δεῖ; πάντως γὰρ τῇ πείρᾳ τοῦτον μαθὼν ἐλάττω νομίσεις τὸν ἔπαινον καὶ ἀσθενῆ με καλέσεις ῥήτορα, ὡς οὐδὲ τὰ προσόντα λέγειν δυνάμενον.