ACC ~ Philippians 3 v3

THE TRUE CIRCUMCISION. AMBROSIASTER: It is evident that those who are faithful are circumcised in their own hearts. By cutting away the cloud of error, they see and recognize the Lord of creation. This is what it means to “serve in the Spirit” and “glory in the Lord Jesus Christ.” EPISTLE TO THE PHILIPPIANS 3.4.

THE SPIRIT ILLUMINES SCRIPTURE. DIDYMUS THE BLIND: The word spirit signifies above all a deeper and mystic meaning in the holy Scriptures. … This construction is supported by [the verse] “We are the circumcision, who serve the Spirit of God and do not trust in the flesh.” ON THE HOLY SPIRIT 249.