(Isa. 49:12)
This phrase may refer to Syene, in southern Egypt, also known as Aswan, where there was a large Jewish colony after the Exile. Or it may refer to the desert of Sin, which is in the peninsula of Sinai. The point is that the Lord will gather his people from wherever they have been scattered. The same is true spiritually. The Lord will find us wherever we are and bring us back to our inheritance, if we will hearken to him and do our part.
(Donald W. Parry, Jay A. Parry, and Tina M. Peterson, Understanding Isaiah [Salt Lake City: Deseret Book Co., 1998], 430.)
Sinim stands for distant lands generally; in the opinion of most scholars it strictly signifies China.
(J. R. Dummelow, The One Volume Bible Commentary [New York: Macmillan, 1936], 445.)