I mentioned that there were some interesting notes concerning the number of Israelites who left Egypt. The word used in the text that is translated as "thousand" is not a cut-and-dry transliteration. Here are some great notes from Ryken on the matter:
The Bible says, “The Israelites journeyed from Rameses to Succoth. There were about six hundred thousand men on foot, besides women and children. Many other people went up with them, as well as large droves of livestock, both flocks and herds” (Exod. 12:37, 38). This account gives the kind of who, what, when, where, how information that a good historian is careful to include. But what about, how many? Can we really believe that God brought so many Israelites out of Egypt?
That’s a good question. If there were six hundred thousand men, then there were perhaps two million Israelites in all, and this number presents a number of difficulties. If there were so many Israelites, then why aren’t they mentioned in the annals of Egypt? They would have formed one of the largest populations anywhere in the world at that time. Could the land of Goshen have supported such a large population? And why can’t we find any trace of them in the Sinai? Their exodus was one of the largest migrations in the history of the world. When they traveled, they must have formed a column more than ten miles long. These are the kinds of questions scholars have asked, with many concluding that whoever wrote the Bible must have inflated the numbers. S. R. Driver wrote that “tradition, in the course of years, greatly exaggerated the numbers of the Israelites at the Exodus.” N. H. Snaith calls the total figures “fantastic and incredible.”9
There are two ways to handle this objection. One is to believe that the Bible does indeed mean to say that 600,000 Israelites (that is, men, plus women and children) came out of Egypt, and therefore this is exactly how many people there actually were. Although some scholars think there are difficulties with that view, there are no impossibilities. The Israelites receive little mention in Egypt because they were only slaves there and because the manner of their departure was such a complete embarrassment to the Egyptians. Nor should we be surprised not to find much evidence for them in the Sinai. They were nomads after all, and their remains have been covered by 3,000 years of sand. In addition, one good reason for accepting 600,000 as the right number is that it matches the statistics given elsewhere in Exodus (38:26) and also in the book of Numbers (see 1:46; 2:32; 26:51).
There is another possibility, however—one that may also be faithful to the Biblical text. The Hebrew word eleph can mean “thousand.” However, early in the Old Testament it may also be used as an inexact term for a sizable cluster of people. Some scholars think it means something like “clan.” Or it may be a military term for a fighting unit, like a platoon. Exodus 12:37 could then be read as follows: “There were about six hundred clans,” or “There were about six hundred military units.” On this reading, the total population of Israelites would have numbered in the tens of thousands, not in the millions.
One scholar who accepts this interpretation is James Hoffmeier, who writes, “The issue in Exodus 12:37 is an interpretive one. The word eleph can be translated ‘thousand,’ but it is also rendered in the Bible as ‘clans’ and ‘military units.’ When I look at the question as an Egyptologist, I know that there are thought to have been 20,000 in the entire Egyptian army at the height of Egypt’s empire. And at the battle of Ai in Joshua 7, there was a severe military setback when 36 troops were killed. If you have an army of 600,000, that’s not a large setback.” It is not a question of whether or not the Bible is true; it is a question of what the Bible means to say. What is certain is that God brought a great crowd of people out of Egypt. Indeed, as the Scripture says, “all the Lord’s divisions left Egypt” (Exod. 12:41).
Source: Philip Graham Ryken and R. Kent Hughes, Exodus: Saved for God’s Glory (Wheaton, IL: Crossway Books, 2005), 352–353.