In the famous story of Hillel HaZaken, he told the convert, “Do not do to others what you would not want to have done to yourself—everything else is a commentary on this central tenet. With this, Hillel was telling him that when you will fulfill the mitzvah of loving another Yid, you will begin to understand the Torah. Because when there is love between Yidden, one soul ignites the other, and when the neshamah is ignited, it discovers the Torah within it, and he begins to understand the Torah and its mitzvos.
Usually, we understand Hillel’s words to say that by fulfilling the mitzvah of כמוך לרעך ואהבת, one will automatically fulfill all the other mitzvos that pertain to the interpersonal relationships which stem from this mitzvah. But according to what we have learned, we understand this on a deeper level: When Yidden love one another, their neshamos become ignited, and each neshamah knows all the mitzvos—including shatnez and shiluach hakein and other mitzvos seemingly unrelated to interpersonal relationships. Thus, a person will know all 613 mitzvos through loving other Yidden.
It is said that when tzaddikim did not have a mikveh in which to immerse, they would say, “ה ישראל מקוה’, Yidden themselves are a mikveh. We can immerse ourselves among Yidden.” Thus, they would bow their heads into the crowd of their chassidim, “immersing” themselves into the love and brotherhood of their fellow Yidden.
