By Avner Friedmann
Many people are under the false impression that rabbinic rulings and ordinances are human add-ons and are therefore not to be taken as seriously as the G_d given commandments explicitly written in the Torah. However, nothing could be further from the truth. In actuality, rabbinic rulings are absolutely integral to Torah and are indispensible to its proper understanding and observance. Moreover, the Torah itself authorizes the rabbis to make legal rulings and obligates us to follow them.
In the first place, of necessity, the written Torah was given alongside the oral Torah, which is its G-d given interpretation. The written Torah itself is extremely terse and had to be explained to be observed in practical terms. For example, everyone knows that Jews fast on Yom Kippur (The Day of Atonement). However, the Torah, merely states, “You shall afflict your souls.” Surely, when our teacher Moshe originally transmitted this commandment to his generation they asked him to elucidate its proper observance. Otherwise, how would they know what to do? Rather, he explained that “affliction” here means fasting, including all the other pertinent details of Yom Kippur observance.
Another example: Shabbat observance is fundamental to Judaism, so much so, that a person cannot be considered to be a Torah observant Jew if he does not keep Shabbat. Even if he keeps all the other 612 mitzvot meticulously, he is not a Torah observant Jew. The written Torah, however, is extremely terse on this subject. It simply tells us to commemorate and keep it, not to work, not to ignite fire and precious little more. Certainly the Jews of Moshe’s generation asked for clarification. Otherwise, how could they put it into practice? The same principle applies to all the mitzvot, such as the dietary laws, Tefillin, Tzitzit etc. etc. Without an oral Torah to explain them, it would be impossible to observe them; not only for us, but even for the generation that originally received them.
However, that we should seek the advice and teachings of our sages concerning Torah practice is more than just a matter of practical necessity. In reality, it too is a commandment written in the Torah, as our Parshah explicitly states, “You shall come to the Levite priests and to the judge who shall be in those days and inquire, and they shall tell you the matter of judgment. You shall act according to the word that they will tell you, from that place that Hashem shall choose (The Holy Temple), and be careful to fulfill everything they instruct you. You shall act according to the teachings they instruct you and the judgment that they tell you; do not deviate from the matter that they tell you, neither to the right or nor to the left.”
In this mitzvah HaShem invests authority and responsibility upon the Sanhedrin (The Supreme Court) and the judges and sages of every generation to instruct the Jewish people in all matters of Torah and it obligates the Jewish people to listen to their teachings and instructions.
On these verses Rashi states that even though the judges and rabbis of our generations may not be on the same level as the rabbis of previous generations and are therefore fallible, we are commanded to follow their judgments. This is so, even if they occasionally err. Sefer HaChinuch adds that it is better to follow an erroneous ruling of the rabbis than to follow our own homespun and arbitrary opinions, because if each person would do only what is fitting and proper in his own eyes, it would lead to spiritual anarchy and chaos and would destroy the very fabric and integrity of Jewish life and tradition.
Moreover, the written Torah authorizes the sages to make a “fence” around the Torah to guard us from even coming close to committing Torah prohibitions, G_d forbid, as it states, “And you shall guard My guarding not to commit any of the abominations that were done before you.” This means they have the G_d given authority and obligation to make additional strictures for the purpose of keeping a person distant from committing an actual Torah prohibition. The laws of Muksah on Shabbat (things that are forbidden to handle on Shabbat) fall into this category.
However, the question still remains. What about the fact that there may be more than one ruling on any given subject? For example Ashkenazic rabbis may rule one way while Sephardic rabbis rule a different way. Moreover, even within these groups, there may be rabbis that rule one way and others that rule a different way. If the Torah was given by One G_d, shouldn’t Torah observance be uniform?
In answer, the Talmud states, “Torah scholars occupy themselves in the deep study of Torah. Some will declare something impure while others will declare it to be pure, some will prohibit something while others will permit it, some will declare something to be unfit while others will declare it to be fit. A person could say to himself, ‘How could I learn (the proper course of conduct) in such a manner?’ However, scripture tells us that (all these opinions) were given by one Shepherd (HaShem) and were declared by one leader (Moshe) who received them from the mouth of the Master of Masters, the Holy One, blessed be He, as scripture states, ‘And G_d spoke ALL these words saying etc.’”
In other words, “Both these and those are the words of the Living G_d”. All are based on deep Torah analysis using the thirteen principles of hermeneutics as received by Moshe on Mount Sinai and therefore all are valid. Even those opinions which never became final Halacha (Torah Law), such as most of the opinions of the academy of Shammai in the Mishnah, were not rejected because they were incorrect, G_d forbid, but because the majority of sages sided with the rulings of the academy of Hillel.
In practical terms, in order to avoid doubt and confusion a person should follow the dictum of Rabban Gamliel, “Make a Rav for yourself, thus distancing yourself from doubt.” This means that you should seek out a learned rabbi who is a Halachic authority that you respect and trust. If you have any doubts about what the Halacha is or how to practice Torah and mitzvot in any way, ask him for his advice and guidance and follow his rulings. In this way, you will be free of doubts.
 Leviticus 16:31
 Deuteronomy 17:9-11
 Rabbi Shlomo Yitchaki, the primary commentator on Torah and Talmud
 Sefer HaChinuch, Mitzvah 496
 Ethics of the Fathers 1:1
 Leviticus 18:30
 Chagiga 3b
 Ecclesiastes 12:11
 Exodus 20:1
 Eruvin 13b
 Introduction to Sifra
 Ethics of the Fathers 1:16