Albert Barnes Commentary Acts 19:13

"But certain also of the strolling Jews, exorcists, took upon them to name over them that had the evil spirits the name of the Lord Jesus, saying, I adjure you by Jesus whom Paul preacheth." — Acts 19:13 (ASV)

The vagabond Jews. Greek: Jews going about. periercomenwn. The word vagabond, for us, is now commonly used in a bad sense, to denote a vagrant: a man who has no home, an idle, worthless fellow. The word, however, properly means one wandering from place to place, without any settled habitation, whatever the cause may be. Here it denotes those Jews who wandered from place to place, practicing exorcism.

Exorcists. exorkistōn. This word properly denotes those who went about pretending to be able to expel evil spirits, or to cure diseases by charms, incantations, etc. The word is derived from orkos, an oath, and from orkizō, to bind with an oath. It was applied in this sense because those who pretended to be able to expel demons used the formula of an oath, or adjured them, to compel them to leave the possessed persons . They commonly used the name of God, or called on the demons in the name of God to leave the person. Here they used the name Jesus to command them to come out.

To call over them. To name, or to use His name as sufficient to expel the evil spirit.

The name of the Lord Jesus. The reasons why they attempted this were:

1. that Jesus had expelled many evil spirits; and
2. that it was in His name that Paul had worked his miracles. Perhaps they supposed there was some charm in this name to expel them.

We adjure you. We bind you by an oath; we command you as under the solemnity of an oath (Mark 5:7; 1 Thessalonians 5:27). It is a form of putting one under oath (1 Kings 2:43; Genesis 24:37; 2 Kings 11:4; Nehemiah 13:25, Septuagint).

That this art was practiced then, or attempted, is abundantly proved from Irenaeus, Origen, and Josephus (Antiquities of the Jews, Book 8, Chapter 2, Section 5). See Doddridge. The common name that was used was the incommunicable name of God, JEHOVAH, by pronouncing which, in a peculiar way, it was pretended they had the power of expelling demons.

Additional notes: Regarding "vagabond Jews," an alternative rendering is "Some of the travelling Jews." Concerning "took upon them to call," see Mark 16:20 and Luke 9:49. Regarding "adjure by Jesus," see Joshua 6:25.