Chazal tell us that just as we were taught all of the generalities and "exactings" [כללותיה ודקדוקיה - Rashi writes פרטותיה - details] of Shmitta at Har Sinai, so too we learned all of the generalities and exactings of the mitzvos at Har Sinai. Why Sinai and why is this emphasized in relation to Shmitta?
The explanation is that there are two types of interrelationships between כללים and פרטים. Sometimes from the details - פרטים we get to the כלל - generality, rule. While at other times from the כלל we get to the details. The difference between them is MASSIVE. The כלל from which details are drawn is INDIVISIBLE [בלתי מתחלק] because it isn't a COMPOSITE כלל [a כלל מורכב] but rather one SOLID כלל. It emerges then that the details that are drawn from the כלל contains a taste of the indivisible כלל. This is in contrast to a כלל that is composed of many פרטים where the כלל is DIVISIBLE [הפרדי] and separable.
That is the difference between ישראל and the עמים. When it comes to the עמים, even if you find a כלל, it is really many individuals coming together. [We discussed this at length in our shiurim on Toras Ha-Rogochover - E.E.]. A כלל composed of many פרטים. In contrast, עם ישראל is a solid כלל which is indivisible and mutatis mutandis [I have been waiting FOREVER to use that in a sentence!!!] each פרט contains a taste of the כלל. For this reason until they arrived at Har Sinai it says "ויסעו ויחנו" - "they travelled and camped" where all that was revealed was the form of the כלל that comes from the fusion of the פרטים. However, when they arrived at Har Sinai it says "ויחן שם ישראל נגד ההר" - They encamped [singular tense] there opposite the mountain - their overriding unity was revealed. That is why we didn't ask Hashem what is written in the Torah [as the nations did]. We weren't concerned with details but just wanted the כלל. As we say every Shabbos Mincha - "אתה אחד ושמך אחד ומי כעמך ישראל גוי אחד בארץ" - "You are One and Your Name is One and who is like your nation Israel one nation in the land." We turned to the כלל, as we said "כל אשר דבר השם נעשה ונשמע" - ALL that Hashem says we will do. Our basic focus in life is on the word of Hashem. Thus, all of the glory of the Torah is from what is revealed at Sinai, a place where the zenith of our elevation was revealed [המקום בו נתגלה מרום פסגתנו], the zenith of the indivisible whole [פסגת הכלל הבלתי מתחלק].
This is where Shmitta comes in. Shmitta teaches us two lessons: ייחוד השם וייחוד ישראל - The uniqueness of Hashem and the uniqueness of the Jewish people. 1] Letting the land lie fallow [שמיטת הארץ] teaches that the earth is the Lord's. 2] The pasuk says "והיתה שבת הארץ לכם לאכלה לך לעבדך ולאמתך" - And [the produce of] the Shabbos of the land shall be yours to eat for you, for your male and female slaves. To say that all of the Jewish people are one and all of their personal acquisitions are revealed to flow from the greater כלל of the years of Shmitta and Yovel. Indeed, the land belongs to the Jewish people they have קנינים and רכוש פרטי - personal property. In the Shmitta year EVERYONE has equal rights to this property. Just as the mitzva of Shmitta with it's פרטים and כללים were stated at Sinai, meaning that both in the פרטים and כללים we taste the unity of the Jewish people and that is the taste of Sinai - so too with all of the mitzvos, all of the כללים and פרטים are from Sinai and are imbued with a taste of our unity.
This is the foundation of the great rule to love fellow Jews. We have to realize that we are all one. This will be fully revealed at the end of days when we will see the חביבות [how beloved] of every individual Jew is as well as the חביבות הכלל.
Now we understand the pasuk in Hoshea "אשר לא ימד ולא יספר" - We have no number or measurement because we are ONE solid, organic, whole.
[עפ"י דברי מרן הגאון רבי יעקב משה חרל"פ זצ"ל]
