John Calvin Commentary Isaiah 49:12

"Lo, these shall come from far; and, lo, these from the north and from the west; and these from the land of Sinim." — Isaiah 49:12 (ASV)

Behold, those from afar shall come. The opinion entertained by some, that the four quarters of the earth are denoted here, does not rest on very solid grounds; yet I do not reject it, because it is not only probable but also agrees with many other passages. Undoubtedly, he first says that they will come from distant parts of the world, and then adds certain subdivisions or parts to explain this general statement.

And those from the land of Sinis. Instead of “Sinis,” some read “Sinis,” and indeed the Hebrew copies differ. Jerome thinks (and this is the commonly received opinion) that a southern region is so named from Mount Sinai, which lay toward the south. Others think that “Syene” is meant, because it lies under the tropic of Cancer.

But this diversity has nothing to do with the meaning of the Prophet, which in itself is clear and easy to understand; for the Prophet unquestionably means those who had been scattered and dispersed in various places, whether they are collected from the north or from the sea.

While Isaiah promises a return from Babylon, he at the same time extends this prediction to the time of Christ, as can be easily learned from what precedes. For we must remember what we previously said: that the second birth of the Church is described here.

He not only promises that the Jews will return to Jerusalem to build the temple, but also that those who had previously been aliens from the Church will be collected from every corner of the world.