Catena Aurea on John 9:8–17: Augustine of Hippo

Some, not all: for some were already anointed. But they, who neither saw, nor were anointed, said, This man is not of God, because he keepeth not the sabbath day. Rather He kept it, in that He was without sin; for to observe the sabbath spiritually, is to have no sin. And this God admonishes us of, when He enjoins the sabbath, saying, In it thou shall do no servile work. (Exod. 20:10) What servile work is, our Lord tells us above, Whosoever committeth sin, is the servant of sin. (c. 8:34) They observed the sabbath carnally, transgressed it spiritually.