Legal Change in Moses Time

A commenter recently said they did not believe the law of ancient Israel was allowed to incorporate change. As this is an important issue, I thought I would say something about it here on the main blog.
Deuteronomy 4:1-2 says:
“ 1 Hear now, O Israel, the decrees and laws I am about to teach you. Follow them so that you may live and may go in and take possession of the land that the LORD, the God of your fathers, is giving you. 2 Do not add to what I command you and do not subtract from it, but keep the commands of the LORD your God that I give you.”
By this God meant that no one should claim God gave commands he did not give or claim that commands God did give were not given by Him. He clearly did not mean there would be no additional revelation from God because there obviously was additional revelation. He also did not mean to bar common law judicial decisions or additional human laws for Israel. I have reasons for believing this:
1) Look at the example of the case of the daughters of Zelophehad in Numbers chapters 26, 27, and 36. The law was modified to deal with a new circumstance, thereby setting the precedent of common law development.
2) Historically, the Mosaic Law did provide for common law style human legal additions. The rabbinic method of expounding the law to new circumstances actually influenced the development of English and American common law methodology.
3) That is how ancient law codes of this type worked and were understood. The Ten Commandments, or the ten words and they are known to the Jews, are the core principles of the code. The other “commands”, like “if a man steals a sheep . . .” etc are exemplar analytic dispositions to serve as guidelines for judges on how to apply the principles in the central Ten Commandments.
4) In practice it has to be that way. No legal code can deal with all possible future human conduct. Additional common law rulings and or statutes will be necessary to deal with new technology, new scams, new threats, and new business patterns that did not exist when the code was made.
5) Better and brighter men than I have interpreted scripture this way. For example, look at the collective teachings of John Calvin in the Institutes.
The Bible also never says other nations have to have exactly the same laws as ancient Israel. These laws were given by God to Israel. Because they came from God, it makes sense to pay attention to the timeless truths they embody. But, a code for an ancient agrarian people is not adequate for a country with cars, computers, nuclear reactors, and banks.