Avram Shannon, “Hebrew,” in Old Testament Cultural Insights, ed. Taylor Halverson (Springville, UT: Book of Mormon Central, 2022).
The language the Old Testament was written in is now known as Hebrew. This is a Northwest Semitic language that belongs the Canaanite group of languages along with Ammonite, Moabite, and Phoenician. According to linguists, the Hebrew language arose from proto-Canaanite sometime around 1,000 BC (around the time of David and Solomon). Our earliest identifiable Hebrew inscription is the Gezer Calendar, which dates to around this era. This means that individuals before the time of David and Solomon, such as Adam and Eve, the matriarchs and patriarchs, or the judges, should not be understood as speaking Hebrew.
After the United Monarchy divided into the Northern Kingdom of Israel and the Southern Kingdom of Judah, Hebrew continued to be spoken in both kingdoms, although there is some evidence of dialectical differences. We see these differences reflected in inscriptions found from both kingdoms.
Within the Bible itself, there are very few specific references to the languages spoken by its various characters. Genesis 31:47 presents Jacob naming a specific site in Hebrew, while Laban names it in Aramaic. Isaiah 19:18 seems to reference Hebrew and calls it the “language of Canaan” (saphaṭ Canaʽan). This is likely a reference to the general mutual intelligibility of the Canaanite languages.
The most explicit reference to the Hebrew language in the Old Testament is found in 2 Kings 18:26–28. There, the Neo-Assyrian army besieged the city of Jerusalem, and the officers sought to intimidate the city through a speech about the invincibleness of the Neo-Assyrian army and the inevitability of defeat. Members of the Judahite ruling class asked the officers to speak to them in “the Syrian language” (saphaṭ Aramit), meaning Aramaic, instead of the “Jew’s language” (saphaṭ Yehudit), meaning Hebrew, so that the people couldn’t understand. The Neo-Assyrians refused (since intimidation was their whole point), but the whole story is instructive on a number of points.
First, it illustrates that the ancient Judahites called their language Judahite, not Hebrew. Second, it shows that educated Judahites would have been expected to know Aramaic, the Neo-Assyrian language of diplomacy, but ordinary Judahites would not have been. Third, we learn that the Neo-Assyrians cared enough about their efforts to intimidate native populations to include individuals in their delegations who spoke the local languages.
After the Babylonian Exile, Hebrew became less of a vernacular because it no longer had a polity associated with it. It continued, however, as a spoken language well into and beyond the New Testament and Second Temple periods. Nehemiah castigated certain members of the community whose children could not speak Hebrew (simply called Yehudit, “Judahite”) in Nehemiah 13:23–25. Hebrew continued to share space with Aramaic as a language for the Jews who returned from exile. Although most of the Hebrew Bible is written in Hebrew, large portions of the post-exilic books of Ezra and Daniel are written in Aramaic.