Acts 21:24

Purify thyself with them. This part of the counsel, when carried out, would be a tacit admission by Paul that he stood in need of cleansing before God. This might be a hindrance to him, not a help, in winning acceptance by the Jews. It would mean entering into the Nazirite abstinence and shaving his head at the close of the time (see on ch. 18:18).

Be at charges. Paul was to assume the expenses of the men who were performing their vows. It meant the cost of the ceremonial shaving, for which the Levite barber would make a charge, and of the sacrifices: two doves or pigeons, a lamb, a ewe lamb, a ram, a basket of unleavened bread, a meal offering, and a drink offering (Num. 6:9-21).

Shaves their heads. At the conclusion of the vow the head was shaved, and when the offerings were made, the hair was burned in the fire lighted under the ram of the peace offering.

All may know. This participation of Paul in the ceremonies of the vows was to convince the Jews that Paul was not an “apostate” from Moses (see on v. 21), and that the things said against him were “nothing.”

Keepest the law. The “Law,” or Torah, was the center of Jewish thinking, life, and religion. The Torah, or teaching, compassed all the instruction given in the writings of Moses. Paul was reputed to have gone against the Law. The only way he could win Jewish approval, the leaders at Jerusalem thought, would be to show that he was faithful to it.