"The dispensation of grace" means the gracious dispensation, oikonomia. As in a well-ordered house prudent economy assigns what each one should do and how, so in the gracious kingdom of Christ, according to the economy of salvation, everything was assigned at the beginning.
It was assigned who should undertake each work and how he should carry it out.
Saint Paul, called directly by the Lord Himself, was likewise commanded by the Lord Himself to go with preaching to the Gentiles: "Go, for I will send you far away to the Gentiles" (Acts 22:21).
Saint Paul recalls here this gracious dispensation or ordinance of the Lord. You know, he says, that preaching among you has been entrusted to me.
I zealously fulfilled my work, but this provoked unreasonable zeal, and here I am in chains.
Saint Chrysostom says: "Here the Apostle alludes to the prophecy announced about him to Ananias in Damascus, when the Lord said: Go, for he is My chosen vessel to bear My name before Gentiles and kings (Acts 9:15).
He calls this revelation the dispensation of grace. Thus the Apostle's words mean this: I learned it not from man. No man counted me worthy of the honor of being your chief evangelist.
Rather, God Himself said: Go, for I will send you far away to the Gentiles (Acts 22:21)."
Saint Paul mentions this not for dogmatic purposes, as in the Epistle to the Galatians, but to give the Ephesians another reason to remember what grace has done for them.
The gracious dispensation regarding him, the Apostle, was directed toward them. With them in view, and showing special care for them, the Lord Himself directly chose and formed the Apostle for them.
He told and revealed everything to him, how and why everything is done, and all of it for them. How could they fail to remember all this?
Saint Chrysostom fixes attention on this formation of the Apostle as a special action of God's dispensation: "The Apostle rightly called this a dispensation. Truly, it was a great dispensation when the one who could not be persuaded by any means was called from above by the words: Saul, Saul, why do you persecute Me? (Acts 9:4), and at the same time lost his sight from the ineffable light."