(My answer to this question at Quora.com)
There are many jokes based on the idea that Hebrew is God’s native language—and inasmuch as all three Abrahamic religions (Judaism, Christianity, and Islam) regard the biblical God as God, in a way it is…
But “Hebrew” is merely the language spoken by the Israelite descendants of Abraham, who was. Living, as they did, in Canaan, it was really just Canaanite, which was spoken by all nations in that country, from Edom and Moab in the southeast to the Phoenicians in Lebanon, and beyond—much as a thousand years ago, the nations we now know as Danes, Swedes, Norwegians, and Icelanders all spoke a common form of Scandinavian.
The Israelites didn’t even refer to the language as “Hebrew”, but rather referred to the speech of each tribe, or region. For example, when Rabshakeh, the Assyrian general who besieged Jerusalem in the time of King Hezekiah (II Kings 18), the senior Judean officials pleaded with him to speak Syrian, not “Judean”, lest the common populace understand his demeaning demands.