Acts 21:26

“Then Paul took the men, and the next day purifying himself with them went into the temple, declaring the fulfilment of the days of purification, until the offering was offered for every one of them.”

It should be noted that there is no suggestion that Paul saw any objection to this at all. It would seem that he willingly and happily carried out the suggestion, joining the Nazirites in the Temple and purifying himself alongside them for their last seven days, so that his own offerings could be accepted, and covering all the costs of their offerings until their vows were satisfactorily completed. There is no hint at all of disapproval in Luke's narrative.

‘Declaring the fulfilment of the days of purification.' That is, declaring to those officiating at the Temple that he was entering into an official seven day purification, and the final seven days of the Nazirite vows. This would ensure that at the final point when the vows were finalised he would be seen as absolutely ‘clean' from any pollution of any kind. It thus confirmed to all that to him being ‘clean' was seen as being important. (This was not just a normal purifying from ‘uncleanness'. That would take place outside the Temple. Paul would not have entered the Temple if he had been ‘unclean'. This was a kind of double guarantee purifying)

There is no reason to doubt that Paul would be quite happy to do this when acting as a Jew among Jews. The previous visit that he had made to Jerusalem had been because of a similar vow (Acts 18:18; Acts 18:22). If he could win Jews to Christ by doing this, or ensure the maintenance of their faith in Christ as Jews, he would be only too pleased to do it, especially as it was so clearly of concern to the leadership of the church who were behaving in an exemplary fashion with regard to the decision made earlier in Jerusalem.

And indeed what happened next cannot really be laid at the door of this behaviour. The men involved were haters of Paul (some of them had been planning to kill him when he sailed from Corinth, and others had tried to kill him in Asia Minor), and they would have constantly been on the lookout for how they could trap him whatever had happened here. They had already revealed that they had an almost pathological hatred for him. Had they not caught him here they would no doubt have caught him this way some other time, unless he avoided the Temple altogether. We do not do well if we blame what followed on this perfectly admirable scheme of the elders at Jerusalem. To do so is simply to reflect our own prejudice. (It is interesting how many who criticise Paul for this expect everyone to be doing the same thing in some supposed Millennium when it would be far less acceptable).