But were all of the Jews at Pentecost necessarily part of a political and geographical Israel? How can they all have been dispersed as a consequence if many who heard and understood the xenolalic tongues were from "every nation under heaven" who had come to worship for Passover and Pentecost, - some emigrants, some residents of other nations and some proselytes who were visitors.
"And there were dwelling in Jerusalem Jews, devout men, from every nation under heaven."
“And how is it that we each hear them in our own language to which we were born? 9 “Parthians and Medes and Elamites, and residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, 10 Phrygia and Pamphylia, Egypt and the districts of Libya around Cyrene, and visitors from Rome, both Jews and proselytes, Cretans and Arabs--we hear them in our own tongues speaking of the mighty deeds of God.”
Acts 2:5, 9-11