The vagabond Jews - Greek: Jews going about - περιερχομένων perierchomenōn. The word “vagabond” with 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, from whatever cause it may be.” Here it denotes “those Jews who wandered from place to place, practicing exorcism.”
Exorcists - ἐξορκιστῶν 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 ὁρκίζω horkizō, “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. Compare Matthew 12:27. 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. Such wanderers and pretenders are common in Oriental countries now. See Land and the Book, vol. i. 224, 510.
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 performed 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, Mar 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 (Antiq., book 8, chapter 2, section 5). See Doddridge. The common name which was used was the incommunicable name of God, Yahweh, by pronouncing which, in a special way, it was pretended they had the power of expelling demons.