Most of the Old Testament was written in Hebrew with a small portion written in Aramaic. The world's languages are classified by linguists in various families based on common characteristics. The Old Testament languages of Hebrew and Aramaic are in the Semitic family. The term Semitic is not used by linguists in a racial sense but in reference to a family of languages of Middle Eastern origin. God's use of different languages in the Bible followed a pattern of focusing first on one region, then widening the scope of the message to include an empire, and finally including the entire known world between India and Ireland. Today, through translation, the Bible is accessible in almost every language known to man.

Hebrew is a dialect of Canaanite and the Canaanites were descendants of Ham, one of the sons of Noah. The Canaanite dialect spoken by the Hebrews is called the Hebrew language. It is called "the language of Canaan" in Isaiah 19:18. The most ancient Hebrew scriptures used the Canaanite style of forming the letters.

The term "Hebrew" has been used to refer to all the descendants of Eber. Eber was the great-grandson of Shem (another son of Noah) and his name means "the other side" and "across". The form "Hebrew", which is derived from "Eber", is intended to denote the people or tribe who came from "the other side of the river" (i.e. the Euphrates River) - from Haran where Abraham and his family migrated to Canaan (Genesis 11:31). "Hebrew" quickly came to refer to a specific branch of Eber's descendants, those who have a covenant relationship with God.

The Hebrew language was written in a script composed of 22 consonants (from right to left) with most Hebrew nouns, verbs, adjectives, and adverbs consisting of only three consonants. Before the middle of the first millenium A.D., the Old Testament text was written without vowels or diacritical marks. Eventually vowels were added because the "ancients" were fearful of losing the ability to pronounce the words as the language became more classical and the texts were no longer those of a living spoken tongue. Some good examples of early Hebrew writing may be found on the Moabite Stone and the Gezer Calendar.

Aramaic uses the same alphabet as Hebrew but the Aramaic style of writing letters was different. Aramaic was a Gentile language but the Jews adopted that style and used it to copy the Holy Scriptures after returning from Babylonian captivity. The common people of Judah spoke Hebrew before the Babylonian captivity, but the elite of Jewish society also spoke Aramaic which was the lingua franca of their region (2 Kings 18:26-28).

Aramaic was known and used by the elite of that region from the eighth century B.C. through the fourth century B.C. It is sometimes called Chaldee in the King James Bible and continued to be a language of major importance until the rise of Islam. The spread of Arab civilization caused another close relative of Hebrew and Aramaic, Arabic, to become the dominant language from Spain to India.

There are at least four Aramaic passages in the Bible - four uses of a different language, not a different style of writing. The first occurs in Genesis 31:47. Jacob had ended a period of exile in Syria and made a formal agreement with his cousin Laban. Laban named the place of agreement in Aramaic, his language, and Jacob gave the equilavent name in his language, Hebrew. The Aramaic term means "Witness Heap".

Jeremiah 10 was written in Hebrew, all except for verse eleven. God is referring to those nations whom He would use to punish His people but those nations would also be judged.

Aramaic is used from the second half of the book of Daniel 2:4 through the end of chapter seven. For prophecies more specifically related to God's people, the nation of Judah, the Scriptures return to the use of Hebrew in chapter eight.

Two official decrees of the Persian Empire are quoted in Aramaic in the Book of Ezra, Ezra 4:8 to 6:18 and Ezra 7:12-26.