When the centurion heard that,.... The question put by Paul, which strongly suggested that he was a Roman:

he went and told the chief captain; what Paul had said: saying, take heed what thou dost; or "art about to do"; lest some bad consequences should follow; lest he should affront the Roman people and senate, and lose his place, if not incur some corporeal punishment:

for this man is a Roman; and it can never be answered to bind and beat a Roman.

When the centurion heard that, he went and told the chief captain, saying, Take heed what thou doest: for this man is a Roman.

22:26 For this man is a Roman. The name Roman acted like magic in each case. The centurion at once pauses, tell his commander to beware; no officer dared to lay a hand in violence on a Roman citizen without trial. The calm was at once allowed, for it was a capital offense to make a false claim of citizenship, and none dared attempt it. Suetonius says:

He who falsely pretended to Roman citizenship was beheaded on the Esquiline hill.''

A constant traveler like Paul would be likely to carry papers that would prove his claims.

22:26 Consider what thou art about to do; for this man is a Roman - Yea, there was a stronger reason to consider. For this man was a servant of God.

22:22-30 The Jews listened to Paul's account of his conversion, but the mention of his being sent to the Gentiles, was so contrary to all their national prejudices, that they would hear no more. Their frantic conduct astonished the Roman officer, who supposed that Paul must have committed some great crime. Paul pleaded his privilege as a Roman citizen, by which he was exempted from all trials and punishments which might force him to confess himself guilty. The manner of his speaking plainly shows what holy security and serenity of mind he enjoyed. As Paul was a Jew, in low circumstances, the Roman officer questioned how he obtained so valuable a distinction; but the apostle told him he was free born. Let us value that freedom to which all the children of God are born; which no sum of money, however large, can purchase for those who remain unregenerate. This at once put a stop to his trouble. Thus many are kept from evil practices by the fear of man, who would not be held back from them by the fear of God. The apostle asks, simply, Is it lawful? He knew that the God whom he served would support him under all sufferings for his name's sake. But if it were not lawful, the apostle's religion directed him, if possible, to avoid it. He never shrunk from a cross which his Divine Master laid upon his onward road; and he never stept aside out of that road to take one up.