Matthew Poole and continuators on 2 Corinthians 3:17

17 Now the Lord is that Spirit , and where the Spirit of the Lord is, there is liberty .

The Lord Christ was a Man, but not a meer Man; but one who had the Divine Nature personally united to his humane Nature, which is called the Spirit, Mark 2.8. But some think, that the Article here, is not meerly Prepositive, but Emphatical; and so referreth to v. 6. where the Gospel (the substance of which is Christ) was called the Spirit. So it is judged by some, that the Apostle preventeth a Question which some might have propounded, viz. how the Veil should be taken away by mens turning unto the Lord? Saith the Apostle, The Lord is a Spirit, or he is that Spirit mentioned v. 18. he is a Spirit, and he gives out of the Spirit unto his People, the Spirit of Holiness and Sanctification.

And where the Spirit of the Lord is, (that holy sanctifying Spirit, which is often called the Spirit of Christ) there is liberty; (for our Saviour told the Jews, Ioh. 8.36. If the Son make you free, then shall you be free indeed) A liberty from the yoke of the Law, from Sin, Death, Hell; but the liberty which seemeth here to be chiefly intended, is a liberty from that blindness and hardness which is upon mens hearts, until they have received the holy Spirit.