The random that is my mind

First awake thought this morning:

Why did God inspire the Old Testament to Hebrew speaking writers and the New Testament to Greek speaking writers?

(I know... even in my sleep, I'm random)

Well, anyway, it occurred to me that the Old Testament was God's Word written primarily to the Jews, regarding His covenant with them, the Law, etc., and Hebrew was the language of the Jews (Israelites). And, the New Testament is God's Word to us regarding Jesus Christ and the New Covenant, which was written in Greek to the Gentiles.  The Greek language was the primary language of that time, a Gentile language.  The New Testament scriptures are, of course, also written for the Jews, describing Jesus Christ as the fulfillment of the Jewish Law.

Did God choose to preserve the New Testament in the Greek language because the Hebrew speaking world had rejected Him?  Or because the Greek speaking world believed He is who He is?  Or was it simply because Greek was the common language of that day?

So... I'm off to do some research.  This is not an eternity-altering subject, but very interesting to say the least.  I will begin by doing a Good Search on "was the New Testament originally written in Hebrew"?  You might want to do some research yourself.  Let me know what you find or think.