A.T. Robertson Commentary Galatians 3:5

"He therefore that supplieth to you the Spirit, and worketh miracles among you, [doeth he it] by the works of the law, or by the hearing of faith?" — Galatians 3:5 (ASV)

Supplieth (επιχορηγων). It is God. See on 2 Corinthians 9:10 for this present active participle. Cf. Php 1:19; 2 Peter 1:5.

Worketh miracles (ενεργων δυναμεις). On the word ενεργεω see 1 Thessalonians 2:13; 1 Corinthians 12:6. It is a great word for God's activities . "In you" (Lightfoot) is preferable to "among you" for εν υμιν (1 Corinthians 13:10; Matthew 14:2). The principal verb for "doeth he it" (ποιε) is not expressed. Paul repeats the contrast in verse 2 about "works of the law" and "the hearing of faith."