Do we have the final say on laws of the Torah?
The Midrash learns some answers from the Book of Ruth
In Chapter 4 of Ruth Rabba, the Midrash addresses issues that seem to contradict the important Torah injunction, 'You shall not add unto the word which I command you, neither shall you diminish ought from it' (Deut. 4 v.2). One is the issue that Moabites are excluded from the Israelite community, 'An Ammonite or Moabite shall not enter the congregation of the Lord' (Deut, 23 v.4); another is instituting the two days of Purim and reading the Book of Esther.
The Midrash takes the last verse of the Book of Leviticus, 'These are the commandments which the Lord commanded Moses for the children of Israel in Mount Sinai' to be the defining parameter of laws that are not to be tampered with.
The significance of the law 'An Ammonite or a Moabite shall not enter the congregation of the Lord' is that King David is the great grandson of Ruth and Ruth is a Moabitess. A king of Israel may not be of Moabite descent. The Midrash stresses that the law excludes, 'A Moabite, but not a Moabitess, an Ammonite, but not an Ammonitess . Why were these nations excluded? For two reasons. One, that when the Israelites were wandering in the desert, these people were hostile, 'they did not bring bread and water to the Israelites (Deut. 23 v,5). Moreover, The king of Moab, Balak, hired Balaam to curse the Israelites (Num.ch.22). The Midrash explains that in both these cases, the women were not involved. It is not fitting for women to do so, it befits a man to do so, le isha she lo le hotzi, ve le ish le hotzi. And, as to hiring Bilaam, it is the man who hires, not the woman, la ish litein s'char ve lo la isha. Incidentally, Maimonides picks up on this. Commenting on Deut 23,4, he says that the Moabite women did sell bread and water to the Israelites, so the reason for Moab's exclusion is the hiring of Balaam. It was the Ammonites who refused bread and water; the question of Balaam does not apply to them. It was therefore permissible, the Midrash states, for Boaz to have children by Ruth the Moabitess, now that Ruth had converted, had, as the Midrash puts it, 'left the fields of Moab'. This whole train of thought was prompted by the verse 'And so Naomi returned and Ruth the Moabite, her daughter-in-law with her, returned from the fields of Moab' (Ruth 1 v.22) and 'Boaz said to his servant..."to whom does that young woman belong?" (Ruth 2 v.5). The Midrash reading of Moses' injunction against the Moabites has made the story acceptable.
The Midrash takes another verse, 'Boaz arrived from Beth Lechem. He said to the harvesters "The Lord be with you". And they answered him "May the Lord be with you" ' (Ruth 2, v.4) as starting point for a different approach to permitting something that has not been permitted. There are three things, explains the Midrash, where the Heavenly Court accepts a decree made by the earthly court. One is based on the verse cited, namely the use of the Name of G-d in a greeting; another is tithing; another is the Book of Esther.
In the case of the Book of Esther, the problems are due to the fact that Purim is not a Biblical festival and that reading the Book (Scroll) of Esther may not be accepted as canon. Both problems seemingly contradict the injunction not to add or take away from the word of the Torah. The Midrash tells that Mordechai and Esther sent letters to all the provinces of Ahasuerus, asking whether the Jews would accept the two days of Purim. The reply was negative; it was bad enough to be under the duress of Haman... A second letter was sent. In the end, the Midrash states, G-d inspired them and they realised that the story of Amalek has to be told in all three parts of the TeNaCh (Torah, Nevi'im and Ketuvim). As Haman is a descendant of Amalek, Haman's persecution of the Jews is, in a way, an Amalekite persecution. We have a strict injunction 'not to forget' Amalek (Deut 25, v 17-19). and we find an allusion in the text of the Book of Esther, about the events that occurred ' Are they not written in the book of chronicles', (Book of Esther 10 v,2), a reference to Ketuvim, the third section of the TeNaCh (Bible). Which is why the Jews took upon themselves (kibelu) the festival and the reading of the Scroll on the festival. The text, says the Midrash, has kibelu in the plural – they decreed; but that is just how the text is read; the letters spell kibel in the singular. (kiyemu ve kibel[u] ha yehudim aleyhem...Esther 9 v.27, the Jews took kibel[u] upon themselves). The plural indicates that the Jews decreed and the singular shows that G-d accepted the decree.
The Midrash has taken pains to show that we have a say in the observance of the Law, whether by new interpretations, as in the law on the exclusion of Moabite men only or by a justified decree, as in the case of the Book of Esther. However, as is clear from the Midrash, the final say is the sanction that is learnt from the Torah.