The Mekhilta identifies one of the hidden miracles of the Egyptian exile: the Israelites never abandoned the Hebrew language. Despite living for centuries among Egyptian speakers, they continued to speak the holy tongue — and this, the rabbis argue, is one of the reasons they merited redemption.
The textual evidence comes from three separate moments in the biblical narrative. First, when Joseph reveals himself to his brothers, the Torah says "the mouth that speaks to you" (Genesis 45:12) — which the rabbis understand as meaning Joseph spoke to them in Hebrew, the holy tongue, proving the family still used it. Second, when Moses and Aaron approach Pharaoh, they announce, "The God of the Hebrews revealed Himself to us" (Exodus 5:3) — using a term that identifies the Israelites by their language. Third, the Torah recalls that when a survivor of the battle of the kings came to report to Abraham, he found "Avram the Hebrew" (Genesis 14:13) — establishing that the designation "Hebrew" was a linguistic and cultural identity stretching all the way back to the first patriarch.
The theological point is striking. The rabbis believed that language preservation was not incidental but essential. A people who keep their language keep their connection to revelation, to prayer, to the words God spoke at creation. Losing your language means losing your ability to hear what God is actually saying. The Israelites held on to Hebrew the way a drowning person holds on to a rope — and that rope pulled them out of Egypt.