Galatians 3:5

He therefore that ministereth to you the Spirit
By whom he means not himself, nor any other minister of the Gospel, in whose power it does not lie to minister the Spirit, either the ordinary or the extraordinary gifts of it unto men; but either God or Christ who had ministered, and still continued to minister the grace of the Spirit through the preaching of the Gospel; or rather the extraordinary gifts of the Spirit, which were manifested at the first preaching of the Gospel to them for the confirmation of it, and which they were still supplied with, as the following words show:

and worketh miracles among you;
so that this is a distinct argument from that in ( Galatians 3:2 ) and a further proof and aggravation of the folly and stupidity of the members of this church, who had not only received through the Gospel the Spirit, as a spirit of regeneration, at least many of them, but had seen the Gospel confirmed by the extraordinary gifts, signs, and wonders of the Holy Ghost, and which were still among them; and yet they were departing from this Gospel, through which all this was done: for it is asked,

doth he it by the works of the law, or by the hearing of faith?
and the apostle's meaning is, that these extraordinary gifts of the Spirit, and these miracles done among them, did not attend the preaching of the law, or the doctrine of justification by works, taught by the false apostles, but the doctrine of faith, of justification by faith in the righteousness of Christ, delivered by him and others, for the truth of which he appeals to themselves; and therefore they must be guilty of the most egregious folly, once to think of, or take anyone step towards a departure from that doctrine. The Alexandrian copy reads here, as in ( Galatians 3:2 ) , "received ye the Spirit by the works of the law, or by the hearing of faith?"