It is also important to note, that Hebrew is not called Hebrew anywhere in Tanach, or Ivrit. It is called Yehudit (see Melachim 2, 18:26. And note in the same place that the Jews didn’t speak Aramiac at that time).
And although some claim it is called lashon hakodesh because it contains no foul words, well for one thing it does, as in the expression עבודת גלולים, which means “dung worship”. What Rambam says is that it contains no words that are directly related to marital relations or to those parts of the body used for marital relations.
But more likely it called the holy tongue because God used it, so to speak, to create the world, and God is called Kadosh.