I'm not very familiar with ancient China but I can tell that 'the land of the - Sinim -' refers to people by plural, that is the way the OT describes nations and places (sometimes).Some of the translations mention Aswan while the others Sinim (a Hebrew plural for Chinese folk) which is probably the source of confusion, there is also the claim it comes from "Sinai" as for Korach descendants.Is there any mention of Chinese Jews in the Old Testament?
Yup.
2. In Isiah 49:12....a verse referred to as 'the Restoration of Israel"
11"I will make all My mountains a road, And My highways will be raised up.
12"Behold, these will come from afar; And lo, these will come from the north and from the west, And these from the land of Sinim."
3. Other verses related....
Matthew 8:11
I say to you that many will come from the east and the west, and will take their places at the feast with Abraham, Isaac and Jacob in the kingdom of heaven.
Isaiah 43:5
Do not be afraid, for I am with you; I will bring your children from the east and gather you from the west.
Isaiah 43:6
I will say to the north, 'Give them up!' and to the south, 'Do not hold them back.' Bring my sons from afar and my daughters from the ends of the earth--
Isaiah 45:22
"Turn to me and be saved, all you ends of the earth; for I am God, and there is no other.
Isaiah 55:5
Surely you will summon nations you know not, and nations you do not know will come running to you, because of the LORD your God, the Holy One of Israel, for he has endowed you with splendor."
Isaiah 59:19
From the west, people will fear the name of the LORD, and from the rising of the sun, they will revere his glory. For he will come like a pent-up flood that the breath of the LORD drives along.
Isaiah 60:4
"Lift up your eyes and look about you: All assemble and come to you; your sons come from afar, and your daughters are carried on the hip.
"...., and nations you do not know...
Well....I don't know Sinim. Maybe it is China....
It is definetly a noun.
Sinim - Wikipedia, the free encyclopedia
Side conclusion: The land of Sinim is the land of the Chinese.
3. So.....is the Isaiah reference "Sinim" what we call China today???
Smith's Bible Dictionary
Sinim a people noticed in (Isaiah 49:12) as living at the extremity of the known world. They may be identified with the classicalSinoe, the inhabitants of the southern part of China.
ATS Bible Dictionary
Sinim Isaiah 49:12, a people very remote from the Holy Land, towards the east or south; generally believed to mean the Chinese, who have been known to Western Asia from early times, and are called by the Arabs Sin, and by the Syrians Tsini.
International Standard Bible Encyclopedia
SINIM, LAND OF si'-nim, sin'-im ('erets cinim; ge Person): The name occurs in Isaiah's prophecy of the return of the people from distant lands:
"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). The land is clearly far off, and it must be sought either in the South or in the East. Septuagint points to an eastern country.
Many scholars have favored identification with China, the classical Sinae. It seems improbable that Jews had already found their way to China; but from very early times trade relations were established with the Far East by way of Arabia and the Persian Gulf;...."
Sin is the name of China (I don't know the origin of the term) however, I know that Sinim is a plural term for Chinese, I don't really think Sinim origin from Sinai by the way it's written in Hebrew, and by Old Commentators (Hazal) it was known people inhabited the far east since the day of Abraham so I tend to believe it does means Sinim as Chinese, rather than anywhere else.