Acts 21:20-24

20When they heard this, they glorified God. Then they said to Paul, “You see, brother, how many thousands of Jews have believed, and all of them are zealous for the law. 21But they are under the impression that you teach all the Jews who live among the Gentiles to forsake Moses, telling them not to circumcise their children or observe our customs. 22What then should we do? They will certainly hear that you have come.

23Therefore do what we advise you. There are four men with us who have taken a vow. 24Take these men, purify yourself along with them, and pay their expenses so they can have their heads shaved. Then everyone will know that there is no truth to these rumors about you, but that you also live in obedience to the law.