“The majority of the essence of the Torah is dependant upon it”. So asserts Rashi as he begins his commentary to parshat kedoshim. It is because of its primary importance, Rashi explains, that these laws of “holiness” were told to “the entire congregation of Israel” and not just from G-d to Moshe. With mitzvot such as honouring parents, Shabbat, paying one’s worker on time, honest weights, respecting the elderly, helping the poor, the prohibitions to gossip, take revenge or bear a grudge, give inappropriate advice, no wonder “the majority of the essence of the Torah is dependant upon it”.
The central mitzva – apparently the essence of holiness – is the Torah’s call to “love one’s neighbour as themselves” (Vayikra 19:18), considered by Rabbi Akiva to be the fundamental principle of the Torah. In doing so, he is elaborating on Hillel’s summation of the entire Torah that, “what is hateful to you, to others you shall not do; this is the entire Torah, all the rest is commentary, go and learn” (Shabbat 31a). We may have heard this teaching hundreds of times, but how often have we contemplated its full meaning.
That giving charity, protecting the stranger, ensuring equal justice for all, or running away from a lie, is little more than and elaboration and explanation of the verse to “love our neighbour as ourselves” is easy to understand.
But what does shabbat, kashrut, fasting on Yom Kippur, sitting in a sukkah or shaatnez, the prohibited mixing of wool and linen, have to do with loving our neighbour? Some might argue that Hillel is referring only to mitzvot between man and man. Don’t do what is hateful to you to others may be a great summary of mitzvot between man and man, but surely has little relevance to mitzvot between man and G-d. However, such an assumption would be incorrect. Hillel does not limit his teaching to just part of the Torah; rather, he specifically says this teaching is “kol haTorah kulah, the entire Torah”. Every single part of the Torah is a commentary on the mitzva to love others as ourselves. Our task is zil gamor, go and learn.
“The reward for fasting is charity” (Brachot 6b). We fast on Yom Kippur in order to develop our sensitivity to the hungry. Only one who has experienced hunger can begin to understand the pain and suffering of those who lack food. Similarly, only one who does not have a roof over their head can know what it means to be homeless. Hence, one week a year we must leave our homes and live in a flimsy hut with a broken roof. The Torah itself – in the ‘Ten Commandments’ no less – teaches that we observe shabbat to remember that we were slaves in Egypt (Devarim 5:15). Over and over again – no less than 36 times (Bava Metzia 59b) – the Torah teaches that as former slaves we are to have extra compassion on the stranger, perhaps the primary purpose of eating matza. It is for good reason we begin the seder with Ha lachma anya – inviting the poor to join us.
At times, as in the examples above, it is easy to see the link between ritual and ethics. With other mitzvot, shaatnez for example, it is more difficult. We must “go and learn”. To give one possible example. The Rambam notes that a Jew should want to eat pork, and refrain from doing so only because G-d has commanded so. There are those who we might like to hate, but we because of G-d’s command we must refrain from doing so.
G-d does not need our mitzvot, it is those created in His image who do. It thus follows that all mitzvot, whether labelled as between man and man or man and G-d are for the benefit of man. These two categories of mitzvot are flip sides of the same coin. Every ritual has an ethical message, and the way we treat others is testimony to our belief in G-d. Every mitzva between man and G-d must strengthen our relationship to our fellow man, and every mitzva between man and man must bring is closer to G-d.
No wonder the Talmud says the first question we are asked in the heavenly court will be Nassata vnatata bemunah, did your business dealings demonstrate emunah, faith in G-d. One who believes in G-d does not cheat in business; it demonstrates one does not believe that G-d is the one who decides whether our business efforts will be met with success. They surely do not believe that “A person’s entire livelihood is allocated to him during the period from Rosh HaShanah to Yom Kippur” (Beitza 16a). One who believes man is created in G-d’s image does not gossip, cheat or lie. Doing so turns one – at least temporarily – into a functional atheist. Belief in G-d is a really hard mitzva to fully observe. It is easy to pay it lip service but translating our belief into action – the true measure of our belief system – is most difficult.
Over and over again our prophets taught that ritual unaccompanied by ethics is not only meaningless but harmful. Such hypocrisy angers G-d. “What need have I of all your sacrifices?” Says the Lord. Who asked you to trample My courts…Incense is offensive to Me. Your new moons and fixed seasons fill Me with loathing; They are become a burden to Me, I cannot endure them” (Yishayahu 1:11-14). Being lax in mitzvot between man and man yet meticulous in ones observance of mitzvot between man and G-d desecrates the name of G-d and makes G-d angry. Picking up on this theme our Talmudic Sages (Yoma 86a) teach that one whose “business practices are not done faithfully and he does not speak pleasantly with other people” it is best that one not observe Jewish law (see here for further elaboration).
If the purpose of every mitzva is to develop our relationship to other people why one may ask do we need mitzvot between man and G-d?
The Rambam opens the Mishneh Torah with the teaching that "the foundation of foundations and the pillar of wisdom is to know there is a First cause”. It is by knowing that there is a G-d, a G-d who created man in His image that we realize the importance of our fellow man. Not realizing this means our knowledge of G-d is greatly deficient. This same Rambam a few chapters later (Laws of Chanukah 4:14) writes, “Peace is great, for the entire Torah was given to bring about peace within the world, as the verse (Mishlei 3:17) states: ‘Its ways are pleasant ways and all its paths are peace.’”
 Presumably Hillel focused on the practical application of this verse because it is not humanly possible to love one’s neighbour as oneself. Perhaps this is why our rabbis understood the verse as referring to one’s spouse. In practical terms our sages understood the verse to treat others as we would want to be treated.
 Many have wondered what the point is to invite the poor to join us by making an announcement to those siting at the table. And if the goal was to invite the poor to join, it would be a rather silly time to do so. Rather, it serves as an announcement that the goal of this most elaborate ritual of the year is to develop our sensitivity to the poor.
 Fascinatingly the various prohibitions of “shaatnez”- crossbreeding animals, seeds and clothing - appears immediately following the verse to love our neighbour as ourselves. Surely shaatnez is much more than avoiding a mixture of wool and linen.