Not his deliverance from captivity, but it will prove salutary to him in a spiritual sense and to the saving work of the Gospel. Salvation simply is used, without any more precise definition; and the broader sense, as related to his ministry, seems to be indicated by the words Christ shall be magnified, in Phi 1:20.
Supply (ἐπιχορηγίας)
See on add, 2Pe 1:5. Compare Gal 3:5. The word implies bountiful supply.
Of the Spirit of Jesus Christ
Either the supply furnished by the Spirit, or the supply which is the Spirit. It is better to take it as including both. The exact phrase, Spirit of Jesus Christ, is found only here. Spirit of Christ occurs Rom 8:9; 1Pe 1:11. The Holy Spirit is meant; called the Spirit of Jesus Christ, because through the Spirit Christ communicates Himself to His people. “The Spirit is the living principle and the organ of the proper presence of Christ and of His life in them” (Meyer).