Before the commandments regarding the arayos, forbidden relationships, the pasuk begins with:
דַּבֵּר אֶל בְּנֵי יִשְׂרָאֵל וְאָמַרְתָּ אֲלֵהֶם אֲנִי ה’ אֱלֹהֵיכֶם – Speak to the children of Israel, and say to them: I am the Lord, your God (18:2).
This is a pasuk that appears frequently in Chumash. Rashi here explains that it is a paraphrase of Sinai, and this rings true for every occurrence of this pasuk and similar:
אני ה’ אלהיכם: אני הוא שאמרתי בסיני (שמות כ:ב) אנכי ה’ אלהיך, וקבלתם עליכם מלכותי, מעתה קבלו גזרותי – I am the Lord, your God: “I am He who said at Sinai (Shemos 20:2) I am the Lord, your God – and there you accepted my Kingship, now you accept my decrees.”
God is instructing Moshe to tell us that in the same way we accepted the yoke of heaven at Mount Sinai, we should now accept His decrees. The instruction to perform mitzvos is based solely on our acceptance of Hashem.
The Sfas Emes explains that this is not just an idea – this is practical advice that can be applied to all mitzvos. The intent upon doing any mitzva needs to be to accept the yoke of heaven. This is the very purpose of the mitzvah. Doing as Hashem instructs confirms that we defer to Him.
With this concept, the Sfas Emes explains why it is that Nadav and Avihu died. The pasuk says: וַיִּקְחוּ בְנֵי אַהֲרֹן נָדָב וַאֲבִיהוּא אִישׁ מַחְתָּתוֹ וַיִּתְּנוּ בָהֵן אֵשׁ וַיָּשִׂימוּ עָלֶיהָ קְטֹרֶת וַיַּקְרִבוּ לִפְנֵי’ ה’ אֵשׁ זָרָה אֲשֶׁר לֹא צִוָּה אֹתָם – And Ahron’s sons, Nadav and Avihu, each took his pan, put fire in them, and placed incense upon it, and they brought before the Lord foreign fire, which He had not commanded them. (10:1)
וַתֵּצֵא אֵשׁ מִלִּפְנֵי ה’ וַתֹּאכַל אוֹתָם וַיָּמֻתוּ לִפְנֵי הֹ – And fire went forth from before the Lord and consumed them, and they died before the Lord. (10:2)
The Sfas Emes explains that אֲשֶׁר לֹא צִוָּה אֹתָם, that they weren’t commanded, was the cause of their deaths, as it was their attitude that led to to the אֵשׁ זָרָה . This should be astounding – they were held responsible not for what they had done, that they offered a foreign fire, but because of their outlook, what they had done represented – they were expressing themselves in a way that God had not asked, and for this they died. It is therefore clear from this episode that our key aim in doing a mitzva should be to do G-d’s will, and the performance of said mitzva should stem from this alone.
Accepting the yoke of Heaven and deveikus, cleaving to Hashem, are interchangeable. When one does a mitzva, their soul moves closer to Hashem, and this develops our relationship with Him. Our relationship grows stronger through the performance of mitzvos, and vice versa with sins. As our perception and feeling to Hashem grows, Hashem comes closer to us too, as it were.
The Sfas Emes explains that this is the translation of the pasuk: וּשְׁמַרְתֶּם אֶת חֻקֹּתַי וְאֶת מִשְׁפָּטַי אֲשֶׁר יַעֲשֶׂה אֹתָם הָאָדָם וָחַי בָּהֶם אֲנִי ה - You shall observe My decrees and My laws, which a man will do and live by them. I am the Lord. (18:5).
וָחַי בָּהֶם is not an instruction, it is a statement. Since the mitzvos are the mechanism through which we draw life into this world, it follows that we can draw life to everything by transforming every action into a mitzvah. Chazal allude to this concept when they say that the wicked, even as they live, are considered dead. This is because they are without mitzvos. וָחַי בָּהֶם – by doing mitzvos, there will be life.
Significantly, the pasuk is in the future tense, “אֲשֶׁר יַעֲשֶׂה אֹתָם – which a man will do,”. The Torah is teaching us to be constantly prepared to do God’s will. Hoping for an opportunity to do God’s will is what this pasuk calls, keeping “My decrees and My laws”. With this approach, when the opportunity arises, we will perform the mitzvah properly and it will have the greatest positive effect on ourselves and our surroundings. Following the beginning of the pasuk leads us to the end result of וָחַי בָּהֶם. Looking for the opportunities to do God’s will is the path to life and happiness.
The Sfas Emes has shown that doing mitzvos is the way we accept Hashem’s kingship. Mitzvos encompass all human activity – there is a way to do everything in a halachically prescribed manner. Hence, by doing mitzvos we can bring all creation closer to Hashem. By doing HaShem’s will, we are accepting His authority, and in so doing we can bring life and joy to the world.