Luke 2:21 - Matthew Poole's English Annotations on the Holy Bible

The time prescribed by the Divine law for circumcision was the eighth day. Genesis 17:12 Leviticus 12:3. He was indeed the lawgiver, and as such not tied to the observance of the law. But he was also made of a woman, made under the law, Galatians 4:4; and the law was, Leviticus 12:2, that if a woman had conceived seed, and borne a man child, in the eighth day the flesh of his foreskin should be circumcised. He was to make himself appear the Son of Abraham; and so this was God's covenant, Genesis 17:10, with Abraham and his seed after him; Every man child among you shall be circumcised. This law Christ was bound to fulfil, and by the fulfilling of it in this point he showed himself a debtor to do the whole law, Galatians 5:3, and by his observance of it he was to teach us our duty. He was to be a minister of the circumcision, Romans 15:8, and to the circumcision, which they would never have allowed him to be, had not he himself been circumcised; upon which account Paul took Timothy, and circumcised him, Acts 16:3. By his circumcision also we were to be circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh, Colossians 2:11. It was therefore reasonable and necessary that Christ should be circumcised the eighth day. His name was called Jesus; it was in circumcision before witnesses publicly declared to be so, for God by his angel had given him his name, Matthew 1:21. We read of four under the Old Testament, to whom God gave names before they were born; Isaac, Genesis 17:19, Josiah, 1 Kings 13:2, Ishmael, Genesis 16:11, Cyrus, Isaiah 44:28; and in the New Testament to John the Baptist, and to Jesus Christ. Which lets us know the certainty to God of future contingencies; for though the parents of Ishmael, and Isaac, John the Baptist, and Christ, imposed those names in obedience to the command of God, and there was but a small time betwixt the giving of these four their names and their birth, yet the case was otherwise as to Josiah and Cyrus.