Answer
The form of Hebrew in the Pentateuch is later than the time of Moses. Moses would not have spoken, written in the precise Hebrew form that we see in the Pentateuch. If you think about it — Moses, if we date him 1400 B.C. or thereabouts, a little bit before that — language changes, and the Old Testament is produced over the course of a thousand years, down to about 450 with Malachi. And so, if the Bible is going to be understandable to the people of God throughout that period, linguistic updating has to happen. But we're confident that God preserved the essential meaning of the text, even though the precise linguistic form changed.
Answer by Dr. Robert B. Chisholm, Jr.
Dr. Robert B. Chisholm, Jr. is Department Chair and Professor of Old Testament at Dallas Theological Seminary.