3 But the Lord, manifestly not disturbed, but calm in His truth, rendered not evil for evil nor railing for railing; although, if He were to say to these men, You have a devil, He would certainly be saying what was true. For they would not have said such things to the Truth, unless the falsehood of the devil had instigated them. What then did He answer? Let us calmly hear, and drink in the serene word: “I have done one work, and you all marvel.” As if He said, What if you were to see all my works? For they were His works which they saw in the world, and yet they saw not Him who made them all: He did one thing, and they were disturbed because he made a man whole on the Sabbath day. As if, indeed, when any sick man recovered his health on the Sabbath day, it had been any other that made such a man whole than He who offended them, because He made one man whole on the Sabbath day. For who else has made others whole than He who is health itself—He who gives even to the beasts that health which He gave to this man? For it was bodily health. The health of the flesh is repaired, and the flesh dies; and when it is repaired, death is only put off, not taken away. However, even that same health, brethren, is from the Lord, through whomsoever it may be given: by whose care and ministry soever it may be imparted, it is given by Him from whom all health is, to whom it is said in the psalm, “O Lord, You will save men and beasts; as You have multiplied Your mercy, O God.” For because You are God Your multiplied mercy reaches even to the safety of human flesh, reaches even to the safety of dumb animals; but Thou who givest health of flesh common to men and beasts, is there no health which Thou reservest for men? There is certainly another which is not only not common to men and beasts, but to men themselves is not common to good and bad. In a word, when he had there spoken of this health which men and cattle receive in common, because of that health which men, but only the good, ought to hope for, he added as he went on: “But the sons of men shall put their trust under the cover of Your wings. They shall be fully satisfied with the fatness of Your house; and You shall give them drink from the torrent of Your pleasure. For with You is the fountain of life; and in Your light shall they see light.” This is the health which belongs to good men, those whom he called “sons of men;” while he had said above, “O Lord, You shall save men and beasts.” How then? Were not those men sons of men, that after he had said men, he should go on and say, But the sons of men: as if men and sons of men meant different things? Yet I do not believe that the Holy Spirit had said this without some indication of distinction. The term men refers to the first Adam, sons of men to Christ. Perhaps, indeed, men relate to the first man; but sons of men relate to the Son of man.
4. “I have done one work, and you all marvel.” And immediately He subjoined: “Moses therefore gave unto you circumcision.” It was well done that you received circumcision from Moses. “Not that it is of Moses, but of the fathers;” since it was Abraham that first received circumcision from the Lord. “And ye circumcise on the Sabbath day.” Moses has convicted you: you have received in the law to circumcise on the eighth day; you have received in the law to cease from labor on the seventh day; if the eighth day from the child's birth fall on the seventh day of the week, what will you do? Will ye abstain from work to keep the Sabbath, or will you circumcise to fulfill the sacrament of the eighth day? But I know, says He, what ye do. “You circumcise a man.” Why? Because circumcision relates to what is a kind of seal of salvation, and men ought not to abstain from the work of salvation on the Sabbath day. Therefore be ye not “angry with me, because I have made a man every whit whole on the Sabbath day.” “If,” says He, “a man on the Sabbath day receives circumcision that the law should not be broken” (for it was something saving that was ordained by Moses in that ordinance of circumcision), why are you angry at me for working a healing on the Sabbath day?
Source: Tractates on the Gospel of John (New Advent)