But when they knew - When they perceived or ascertained.
That he was a Jew - There was a general prejudice against the Jews. They were disposed to charge the whole difficulty on Jews - esteeming Christians to be but a sect of the Jews. They were, therefore, indiscriminate in their wrath, and unwilling to listen to any defense.
With one voice - Unitedly, in one continued shout and clamor.
About the space of two hours - The day, from sunrise to sunset, among the Greeks and Romans, was divided into twelve equal parts, John 11:9. An hour, therefore, did not differ materially from an hour with us. It is not at all improbable that the tumult would continue for so long a time, before it would be possible to allay the excitement.
Cried out ... - This they at first did to silence Alexander. The shouting, however, was continued in order to evince their attachment to Diana, as would be natural in an excited and tumultuous mob of pagan worshippers.