John 7:19-24 Did not Moses give you the law, and yet none of you keep the law? Why go you about to kill me? The people answered and said, Thou hast a devil: who go about to kill thee? Jesus answered and said unto them, I have done one work, and you all marvel. Moses therefore gave unto you circumcision; (not because it is of Moses, but of the fathers;) and you on the sabbath day circumcise a man. If a man on the sabbath day receive circumcision, that the law of Moses should not be broken; are you angry at me, because I have made a man every whit whole on the sabbath day? Judge not according to the appearance, but judge righteous judgment.
Moses gave the nation of Israel the Law as he received it from God, and the whole summary of the Law (Matt. 22:37-40) was to love God, serve AND obey Him (Deut. 6:5; 7:9; 10:12; 11:1, 13). Jesus accused the Pharisees of violating the very law they professed to respect and obey, they only kept up the Law for outward appearance that would produce the praise of men and produce followers for their religion (Matt. 23).
Many strangers (people) at the feast were ignorant of the plots of the Pharisees to killed Jesus, so they were astonished at His announcement that they seek Him to kill Him.
This ‘one work’ from verse 21 was the healing of the man on the sabbath (John 7:23; 5:1-16). The Pharisees accused Him of breaking the law and, in the interest of religion, thought He should be killed. He replied that they did more work on the sabbath in circumcising a boy than He did in healing a man, so who was the greater sinner?
The law concerning circumcision was given to Abraham (Gen. 17:9-14); Moses only mentioned the law in Exodus 12:44, 48 and Leviticus 12:3.
‘Judge not according to the appearance’ – Jesus answered those who tried to kill Him for obeying His Father that the covenant of healing (Ex. 15:26) should be obeyed as much as the covenant of circumcision (Gen. 17:9-14); that sickness in their midst proved that they had broken God’s covenant.