Matthew Henry,
"He broke down the middle wall of partition, the ceremonial law, that made the great feud, and was the badge of the Jews' peculiarity, called the partition-wall by way of allusion to the partition in the temple, which separated the court of the Gentiles from that into which the Jews only had liberty to enter. Thus he abolished in his flesh the enmity, Ephesians 2:15. By his sufferings in the flesh, to took away the binding power of the ceremonial law (so removing that cause of enmity and distance between them), which is here called the law of commandments contained in ordinances, because it enjoined a multitude of external rites and ceremonies, and consisted of many institutions and appointments about the outward parts of divine worship. The legal ceremonies were abrogated by Christ, having their accomplishment in him. By taking these out of the way, he formed one church of believers, whether they had been Jews or Gentiles. Thus he made in himself of twain one new man. He framed both these parties into one new society, or body of God's people, uniting them to himself as their common head, they being renewed by the Holy Ghost, and now concurring in a new way of gospel worship, so making peace between these two parties, who were so much at variance before. 2. There is an enmity between God and sinners, whether Jews and Gentiles and Christ came to slay that enmity, and to reconcile them both to God, Ephesians 2:16."
Henry supports this as being the Law that seperated them. Both parties now able to worship Him as individual believers whether Jew or Gentile.