Matthew Poole and continuators on Acts 2:5

5 And there were dwelling at Jerusalem, Jews, devout men, out of every nation under heaven .

Not onely constant Inhabitants, but such as had on occasion their Lodgings there▪ partly, out of a constant respect, which both Iews and Proselytes had for that place, (for the Temple and their worship sake; it being also a place for Learning and Education, as appears by the Colledges and Synagogues mentioned, Chap. 6. ver. [illegible: 1 letter].) But especially now the concourse from all parts must needs have been very great; it being one of those times in which all the Males were to appear before God. To which might be added, the great expectation they had of the Messiah, made them to omit no occasion of inquiring concerning him; the Prophecies concerning the time of his coming being fulfilled, and they could not be ignorant of the many and great things concerning the true Messiah

Whether the Iews had been dispersed in the two or three greater, or other lesser dispersions: Thus in part was fulfilled what was Prophesied, Isa. 43.5.