Peter On Paul, Paul On Peter

Sicut et charissimus frater noster Paulus secundum datam sibi sapientiam scripsit vobis. Paulum illis scripsisse commemorat, quia etsi Paulus ad quasdam specialiter scripsit Ecclesias, omnibus tamen generaliter, quae per orbem sunt, quaeque unam catholicam faciunt, scripsisse probatur Ecclesiis. Et notandum quod hic Petrus Pauli sapientiam laudat, ipse autem Paulus de se dicit: Ego enim sum minimus apostolorum, qui non dignus vocari apostolus, quoniam persecutus sum Ecclesiam Dei. Ecce se Paulus priscae suae infidelitatis memor humiliat, et aliorum apostolorum innocentiam praefert. Ecce primus apostolorum, quasi oblitus sui prioratus, et datarum sibi clavium regni, datam Paulo sapientiam miratur. Quia nimirum moris est electorum ut aliorum magis quam suas mirentur virtutes, per quas se ad profectum excitent. Itemque notandum quod Paulus in Epistolis suis  dicit: Cum autem venisset Cephas Antiochiam, in faciem ei restiti, quia reprehensibilis erat. Reprehendit ergo Paulus in Epistolis suis Petrum, et tamen ipse Petrus, easdem epistolas relegens, laude eas dignas judicat. Quia nimirum hoc ipsum quod se in illis merito reprehensum invenit, non quasi injuriam aspernanter, sed gratulanter quasi officium devotionis accepit. Tales esse ad invicem non quilibet mortalium, sed illi soli norunt, qui didicerunt a Domino mites esse et humiles corde, qui sciunt honore invicem praevenire. Sancta Beda,  In II Epistolam Sancti Petri Migne PL 93 83-84

As even our most dear brother Paul, according to the wisdom given to him, wrote to you. 1 He recalls that Paul wrote to them, because even if Paul wrote to certain designated churches, yet to everyone in general, throughout the whole world, whoever are of the one Catholic faith, he has written what is approved by the churches. And it should be noted here that Peter praises the wisdom of Paul, that same Paul who said concerning himself, 'I am the least of the Apostles, one who is not worthy to be called an Apostle, because I persecuted the Church of God.' 2 Behold Paul humbling himself in the recollection of his old unfaithfulness and bringing forward the innocence of the other Apostles. And behold the first of the Apostles, first because he forgets his own priority and the giving to him of the keys of the kingdom, 3 and admires the wisdom given to Paul. Truly it is the way of the elect that they admire more the virtues of others than their own, by which they rouse themselves to improvement. And again let us note that Paul said in his letters 'When Cephas came to Antioch, I opposed him to his face, because he was worthy of reproach.' 4 Thus in his letters Paul reproves Peter, and yet when Peter composes his own letters, he judges Paul worthy of praise, because he finds that he did indeed merit reproof in these things, and he smarts at it not as an injury, but gladly receives it as the duty of devotion. That such things be is not given to mortal men, but they alone know it who are taught by the Lord to be meek and humble in heart, who understand that they should come before one another with honour. 5 Saint Bede, from the Commentary on the Second Letter of Saint Peter 1 2 Pet 3.15 2 1 Cor 15.9 3 Mt 16.19 4 Galat 2.11 5 Rom 12.10