The mitzvah of “ve’ahavta le’reacha kamocha” (Vayikra 19:18) is spelled out explicitly in the Torah. According to Rambam’s Sefer HaMitzvos, and Sefer HaMitzvos HaKatzer, it is counted as one of the positive commandments. It is an emotionally-driven mitzvah that is immediately preceded by two other emotion-based mitzvos: “lo sitor v’lo sikom,” the prohibition of bearing a grudge or taking revenge. These two mitzvos are included in his counting of the negative commandments. It is far easier to follow the rules of a negative commandment, however, considering all that is necessary is abstinence from doing the prohibited action. Rashi there explains clearly that if your neighbor doesn't let you borrow his sickle and the next day he asks to borrow your hatchet, you cannot deny him the loan if the denial is motivated out of a sense of revenge. Additionally, you cannot explain that you are lending it because you're better than he is; such an action would constitute bearing a grudge.
Rashi points out in his commentary to “ve’ahavta le’reacha kamocha” that R. Akiva states it is a “klal gadol ba’Torah.” What makes it “a great rule in the Torah,” though? Why is loving someone else so crucial to the essence of Torah and, by extension, what it means to be a Jew? Even more importantly, how is one supposed to ingrain in him or herself a love for another person? Indeed, it is not just one person with whom one must cultivate a real relationship with, but an entire nation of people who also happen to be strangers.
What’s The Big Deal?
The first question is answered much more simply than the second. Rashi gives two options for why R. Akiva classifies this mitzvah as one of such great importance. He explains (Shabbos 31a) that a majority of the mitzvos are in fact bein adam la’chavero and therefore a klal gadol. The other explanation is that at times HaShem is referred to as “Re’ah” and therefore this mitzvah can be applied to HaShem, thus creating an edict of Ahavas HaShem.
Even without Rashi’s commentary, it follows logically that loving your fellow would make all other positive commandments easier to adhere to. Giving charity, doing chessed, visiting the sick, praying on behalf of others… these are all things made easier by loving and appreciating the person whom you are servicing.
The second question posed is therefore a much more challenging one to understand. How does one foster the proper emotional mindset to fulfill such a seemingly open-ended commandment?
A Possible Explanation
In Peninei Halacha R. Melamed poses our question. He asks how it is possible to command someone to love in the first place. He says “the heart cannot just fulfill a command; if he loves — good, and if not — this command isn't going to help” (Likutim Bet). R. Melamed then suggests a somewhat unsatisfactory answer: He explains that this mitzvah is not referring to an external love. Rather, this mitzvah is actually somewhat unnecessary as there is actually an inherent love that exists between all Jews, as brothers and sisters, deep down. The Torah is just guiding us to reveal this love to one another.
Hillel helps make this commandment into something that is more readily fulfilled. He says “that which is hateful to you, do not do to your fellow” (Shabbos 31a). Maharsha explains that Hillel is actually defining halachik parameters to keeping the passuk of “ve’ahavta le’reacha kamocha” based on the fact that it immediately follows the negative commandments against bearing a grudge and taking revenge. The mitzvah is therefore limited to what one shouldn't do rather than what one should do. This answer also seems to be lacking something. Though having a list of what not to do makes it easier to fulfill the mitzvah at a technical level, it definitely cuts out the aspect of Ahavas Yisrael that seemed to define the mitzvah in the first place.
Turning To Purim
That’s where the Purim story comes in handy. Everything about the Purim story is centered around the theme of Ahavas Yisrael. From Esther sacrificing herself for the sake of the continuity of the Jewish nation, to everyone fasting together, the realization of needing the nation intact, as a whole, is what drives the story.
At the very end of Megillas Esther, the fourteenth of Adar is set aside to be a day of simcha and a day where “each man gives packages to his fellow” (9:19). The Megillah uses the word “re’ah” — the same word as in the original commandment in Vayikra. The purpose of Mishloach Manos is to cultivate a love amongst Jews. When everyone is giving freely and receiving packages, the feeling of love in the air is palpable. Chazal teach that “after actions, the heart follows” meaning that external actions have major repercussions on the internal self.
R. Melamed advises that one should take this adage to heart and that if one isn't feeling the love, he should help other people, judge them favorably, and do chessed for them. After one invests that kind of energy into another person, one can’t help but love him or her.
On it’s own, what R. Melamed suggests seems a little esoteric and challenging due to the still emotionally-based halachik parameters, but coupled with Hillel’s advice and the Megillah’s command, the challenge to “love thy fellow as thyself” is no longer quite as daunting. The commandment and what it necessitates come together in a cyclical fashion.
In order to cultivate love, one must help and give to others; in order to help and give to others, one must love his fellow.