10.He who is washed needeth not to wash more than his feet, but is altogether clean. First, he says that believers are altogether clean; not that they are in every respect pure, so that there no longer remains in them any stain, but because they are cleansed in their chief part; that is, when sin is deprived of its kingly power, so that the righteousness of God holds the superiority; just as if we were to say, that a body was altogether healthy, Because it was not infected with any universal disease. It is by newness of life, therefore, that we must testify ourselves to be the disciples of Christ, for he declares that he is the Author of purity in all his followers.
Again, the other comparison was also applied to the case in hand, that Peter might not set aside the washing of the feet as foolish; for, as Christ washes from the head to the feet, those whom he receives as his disciples, so, in those whom he has cleansed, the lower part remains to be daily cleansed. The children of God are not altogether regenerated on the first day, so as to aim at nothing but the heavenly life; but, on the contrary, the remains of the flesh continue to dwell in them, with which they maintain a continued struggle throughout their whole life. The term feet, therefore, is metaphorically applied to all the passions and cares by which we are brought into contact with the world; for, if the Holy Spirit occupied every part of us, we would no longer have anything to do with the pollutions of the world; but now, by that part in which we are carnal, we creep on the ground, or at least fix our feet ill the clay, and, therefor are to some extent unclean. Thus Christ always finds in us something to cleanse. What is here spoken of is not the forgiveness of sins, but the renewal, by which Christ, by gradual and uninterrupted succession, delivers his followers entirely from the sinful desires of the flesh.
And you are clean. This proposition may be said to be the minor in the syllogism, and hence it follows that the washing of the feet applies to them with strict propriety.
But not all. This exception is added, that every one may examine himself, if Judas may perhaps be moved by a feeling of repentance; though he intended by it to take an early opportunity of fortifying the rest of the disciples, that they might not be perplexed by the atrocity of the crime, which was soon afterwards to be made known. Yet he purposely abstains from naming him, that he may not shut against him the gate of repentance. As that hardened hypocrite (44) was utterly desperate, the warning served only to aggravate his guilt; but it was of great advantage to the other disciples, for by means of it the Divinity of Christ was more fully made known to them, and they likewise perceived that purity is no ordinary gift of the Holy Spirit.