He was there with the Lord forty days and forty nights. — As on his former ascent (Exodus 24:18). The long time is, at first sight, surprising, since there were now no instructions to be given. But we learn from Deuteronomy (Exodus 9:18-19) that it was required for an earnest and prolonged intercession by Moses on behalf of his nation, which ultimately prevailed with God, and induced Him to put away His “anger and hot displeasure.”
He did neither eat bread, nor drink water. — A similar fast had been kept on the previous occasion (Deuteronomy 9:9), though it is not mentioned in Exodus. Fasts of this extraordinary duration are only recorded of Moses, of Elijah (1 Kings 19:8), and of our Lord (Matthew 4:2). They are absolutely miraculous, and modern attempts to rival them are viewed by scientific men as deriving such apparent success as may have attended them from imposture.
He wrote upon the tables. — It has been concluded from this statement that Moses engraved the words upon the second tables; and the passage, if it stood alone, would certainly admit, and, indeed, naturally suggest, this meaning. But the Hebrew idiom allows us to regard Jehovah as the nominative to the verb “wrote;” and it is necessary so to do in order to bring the passage into agreement with Exodus 34:1. and with Deuteronomy 10:2; Deuteronomy 10:4. Thus the second tables are to be viewed as “written with the finger of God” no less than the first (Exodus 31:18; Exodus 32:16).