G‑d gave the Jewish nation 613 mitzvahs in the Torah. There are seven additional mitzvahs that the prophets and rabbis of the ancient judicial courts initiated during the first millennium after the giving of the Torah on Mount Sinai. The rabbis also instituted many additional decrees for the purpose of preserving the original 613 commandments.

When a rabbinical court institutes a new mitzvah or decree, and it is accepted among the Jewish nation, it becomes a part of Torah and Judaism. In fact, the Torah states, “According to the law they [the rabbinical courts] instruct you and according to the judgment they say to you, you shall do; you shall not divert from the word they tell you, either right or left.”1 Thus the Torah commands us to heed the instructions of the great rabbinical courts.

More on how that works2

1. Saying Hallel

The mitzvah of saying Hallel is to recite Psalms 113-118, which praise G‑d, on certain special occasions.

Hallel is recited on the festivals of Sukkot, Shemini Atzeret (Simchat Torah), Chanukah, Passover and Shavuot to show our gratitude to G‑d for the miracles that we are commemorating at those times. Each of these festivals celebrates the miracles that G‑d has performed for the Jewish nation. One of the ways of expressing our gratitude is by reciting Hallel. By extension, there is an ancient custom to recite a truncated Hallel on Rosh Chodesh (and the final six days of Passover).

2. Blessings

The rabbis scripted various blessings (berachot) of praise and gratitude to G‑d to be recited on all sorts of occasions. There are numerous blessings that are said before one has the pleasure of eating, drinking or smelling fragrances. There are also blessings that are recited before doing a mitzvah. Each category of food or smell, and each mitzvah, has its own prescribed blessing. There are also blessings that are said upon witnessing a spectacular natural phenomenon, like when seeing a shooting star. There are also blessings said when switching from mediocre to great wine, when returning to a place where a miracle has occurred to oneself or to one’s ancestors, when seeing a friend after an extended period of time, when entering a cemetery, when seeing a beautiful person, when seeing certain animals and more.

How to make blessings before foods

3. Washing Hands Before Eating

Before eating bread one must wash one’s hands in a prescribed manner. The reason for this is that sacred foods and Temple offerings may not be eaten in ritual impurity. The rabbis decreed that, since people are constantly touching all sorts of stuff, hands must be treated as though they are impure. The way to rid oneself of this impurity is through this hand-washing. To ensure that the hands will be washed before sacred foods are eaten, the rabbis extended this law and decreed that one should wash one’s hands anytime bread is eaten.

More on why we wash our hands

More on how to wash our hands

4. Eruv on Shabbat

The rabbis placed certain restrictions on Shabbat and festivals. The eruv is a mechanism that makes these restrictions more permissive. There are three kinds of eruvs:

1. On Shabbat, the Torah prohibits carrying anything from an enclosed area to an open area, or vice versa. It is also prohibited to carry for more than four cubits within an unenclosed, public area, known as a reshut harabim. The rabbis extended this prohibition to a less public area, known as a karmelit. Thus one may not carry a baby or a book down a street, from a house to a street, or from a street into a house. The purpose of the eruv is to solve this extreme inconvenience. The eruv transforms the entire area in which one wishes to carry into one enclosed domain. By joining the numerous enclosed and unenclosed domains together, carrying becomes permitted, just as carrying within a house is permitted. An eruv can be made large enough to contain entire neighborhoods, or it can be made around a small area, like a driveway or sidewalk next to a house.

Making the eruv is a two-step process. First a technical enclosure is made of a series of walls, strings mounted on poles, steep hills or wires.

The next step is for everyone living within the enclosure to own food together. This can be accomplished either by collecting a small amount of food from all the Jews who live within the enclosure, or by one person giving ownership of some of his food to the others. Since the area is enclosed, and the residents are sharing food (albeit symbolically), it is considered like one house, in which carrying is permissible.

More on how and why the eruv works

2. The second kind of eruv is called eruv techumin. On Shabbat and festivals, the rabbis forbade one to walk further than 2,000 cubits away from the most outlying residence of a city. If one wishes to walk further than this distance on Shabbat, one must create a temporary residence beyond that outlying residence. This extends the city border and allows one to walk up to 2,000 cubits from that temporary residence. The way to create this residence is by placing food past the edge of the city before Shabbat or the festival begins.

3. The third kind of eruv is called eruv tavshilin. One of the differences between the festivals and Shabbat is that on the festivals one may cook on a pre-existing flame, while all cooking is prohibited on Shabbat. However, even on festivals, one may cook only what will be used during that day, and not with the intent of using the food after the festival. A problem arises when a festival falls on a Friday. When should food be prepared for Shabbat? One may not prepare food on on a festival for the next day, and to cook on Shabbat itself is also not allowed. To resolve this, the rabbis decreed that two food items should be prepared and set aside for Shabbat before the holiday, symbolically serving as the beginning of the preparation of food for Shabbat. Thus, any subsequent cooking done on the festival is considered to be a continuation and completion of the preparation that was begun earlier, and is therefore permitted. The food that is prepared before the holiday for this purpose is known as eruv tavshilin.

More on eruv tavshilin

5. Shabbat Candles

On Friday evenings, right before the beginning of Shabbat, every Jewish home must light a candle (generally at least two) in honor of the special day. Candles are also lit before the onset of Rosh Hashana, Yom Kippur, Sukkot, Shemini Atzeret (Simchat Torah), Passover and Shavuot. The Rabbis introduced this practice to ensure that Shabbat and festivals should be peaceful and calm, without people tripping or stumbling in the dark.

More on why we light candles

How to light candles

6. Purim (Megillah)

In the year 355 BCE, the Jewish nation was miraculously saved from extermination by Queen Esther and Mordechai. The sages of that time, at the request of Queen Esther, instructed all Jews to celebrate a joyous festival called Purim on the 14th (or 15th) of the month of Adar, which is the anniversary of the salvation.

There are four mitzvahs of Purim that are part of the celebration. The dramatic story was written down in the Megillah (Scroll) of Esther. We read the Megillah once on the eve of Purim and once on the following day. The other mitzvahs of Purim are to have a festive feast, to give two gifts of food to another Jew, and to give money to at least two poor people.

All about Purim

7. Chanukah

This festival was enacted on the first anniversary of the victory of the Maccabees over the Greek army in the year 139 BCE. When the Jews returned to the Holy Temple after the war, they found only one small jug of oil with which to kindle the Temple Menorah. Miraculously, the insufficient oil kept on burning for eight days, by which time other oil was imported.

On Chanukah we celebrate the victory of the small Jewish army recapturing the Holy Temple, and the miracle of the small jug of oil.

Chanukah is eight days long beginning on the 25th of the month of Kislev, which is when the Jews jubilantly returned to the Temple to repair and redecorate it, and when the miracle of the oil took place. The mitzvahs of Chanukah are to light the menorah, and to recite Hallel in thanks to G‑d for the miracles he performed.

All about Chanukah