I was struck by the fact that Rashi and Ramban have diametrically opposed interpretations of the last pasuk in our parsha:
וַיַּ֥עַשׂ אַהֲרֹ֖ן וּבָנָ֑יו אֵ֚ת כׇּל־הַדְּבָרִ֔ים אֲשֶׁר־צִוָּ֥ה ה׳ בְּיַד־מֹשֶֽׁה
Rashi comments:
ויעש אהרן ובניו – להגיד שבחן, שלא הטו ימין ושמאל
The kohanim did exactly as instructed, with no deviation.
Ramban, on the other hands, notes the expression used in our pasuk, אֲשֶׁר־צִוָּ֥ה ה׳ בְּיַד־מֹשֶֽׁה, is unusual. Usually we see the phrase כּאשר צוה ה׳ את משה. Why the difference here? He explains:
אבל בכאן מפני שהוסיפו על המצוה, לא אמר כן, כי לא עשו כאשר צוה השם, אבל עשו כל הדברים אשר צוה השם, ועוד נוסף עליהם מה שיאמר באש זרה: אשר לא צוה אותם
The kohanim did exactly as instructed, plus. That plus is a deviation that, as we will read in next week's parsha, would lead to tragedy.
I understand the need to tell us that things did not go according to plan. However, according to Rashi, why does the fact that things did go according to plan warrant a mention? Clearly the Torah does not tell us every time Moshe gave some command or mitzvah that Bn"Y obeyed as instructed. It's assumed. So why would we not make that assumption here? We does the Torah have to spell it out?
This is not the only place we find this phenomenon. One other well known example occurs in the parsha of lighting the menorah (BaMidbar 8:3)
וַיַּ֤עַשׂ כֵּן֙ אַהֲרֹ֔ן אֶל־מוּל֙ פְּנֵ֣י הַמְּנוֹרָ֔ה הֶעֱלָ֖ה נֵרֹתֶ֑יהָ כַּֽאֲשֶׁ֛ר צִוָּ֥ה ה׳ אֶת־מֹשֶֽׁה
Rashi: ויעש כן אהרן – להגיד שבחו של אהרן שלא שינה.
Maharal in Gur Aryeh explains why the fact that Aharon did as instructed warrants mention:
וקשה, מאי שבח יש בזה שהיה מדליק המנורה, ויש לתרץ, דהוצרך צמצום גדול לצמצם שיהיו כולם נגד האמצעי ממש, והוצרך לצדד אותם.
Another example that has to do with Pesach, since it is inyana d'yoma (BaMidbar 9:5):
וַיַּעֲשׂ֣וּ אֶת־הַפֶּ֡סַח בָּרִאשׁ֡וֹן בְּאַרְבָּעָה֩ עָשָׂ֨ר י֥וֹם לַחֹ֛דֶשׁ בֵּ֥ין הָעַרְבַּ֖יִם בְּמִדְבַּ֣ר סִינָ֑י כְּ֠כֹ֠ל אֲשֶׁ֨ר צִוָּ֤ה ה׳ אֶת־מֹשֶׁ֔ה כֵּ֥ן עָשׂ֖וּ בְּנֵ֥י יִשְׂרָאֵֽל׃
Sifri darshens: ככל אשר צוה י״י את משה – להודיע שבחן של ישראל שכשם שאמר להם משה כן עשו.
Here too, Maharal (on our pasuk) explains why the fact that Bn"Y followed instructions warrants mention: מפני כי הפסח הוא מוטל על כל יחיד ויחיד לעשות הפסח, ולא כמו שאר המצות, כי קרבן זה יש לו שעה ידועה ומוגבלת לכל ישראל:
(Parenthetically, why does Rashi in our parsha and Rashi in the parsha of lighting menorah quote the derash of להגיד שבחו or להגיד שבחן, but he doesn't do so in that parsha of korban pesach? The Sifri has the derasha, but Rashi is silent. I don't have an answer yet.)
Coming back to Tzav, I want to offer three possible explanations as to why Aharon and sons are praised for not deviating from the dvar Hashem.
The miluim were a seven day prep and training period for Aharon and his sons to learn how to do avodah. When you have a period of time set for training, you don't expect a person to perform the same on day #1 as on the final day. Let's say you decide to devote six months to learn to play the piano One would hope that on the last day of month 6 your playing is significantly better than on the day you started. In our case, the praise of שלא הטו ימין ושמאל is not talking about what happened only on day seven of the miluim, but is talking even about day one. Not only did Aharon or his sons not err in a way that would pasel a korban, but, explains the Lubavitcher Rebbe, לא הטו, they did not make the slightest deviation, the slightest error, even something that was not l'ikuva. It would be like sitting down at that piano on day #1 with no prior training and banging out a flawless rendition of Rachmaninoff's Concerto No. 2 (enjoy!). Only someone who is completely connected to what he is doing can pull that off. לֹא יְאֻנֶּה לַצַּדִּיק כׇּל אָוֶן (Mishlei 12:21) That was the special bracha of Aharon.
Another answer is offered by Maharal based on a Chazal:
אלא שעשו זה בשמחה לקיים מה שאמר להם משה כאילו שמעו מפי הגבורה. ... דזה שייך כאן, כי דרך עולם – גדול שנצטווה מאחר, אינו עושה בשמחה שהוא ישמע לאחר, אבל אהרן היה שמח כאילו בעצמו שמע.
Even though the commands were given בְּיַד־מֹשֶֽׁה and not to him directly, and no one -- not even the great Aharon -- likes to receive orders from someone else and be bossed around, that didn't diminish Aharon's simcha, that didn't diminish he meticulousness.
I wanted to suggest reason that the praise warrants mention here. The Tanchuma at the beginning of next week's parsha writes as follows:
זֶה שֶׁאָמַר הַכָּתוּב: שׁוֹמֵר מִצְוָה לֹא יֵדַע דָּבָר רָע (קהלת ח, ה). מִי הָיָה. זֶה אַהֲרֹן שֶׁנֶּאֱמַר: וּמִפֶּתַח אֹהֶל מוֹעֵד לֹא תֵּצְאוּ שִׁבְעַת יָמִים, וּפֶתַח אֹהֶל מוֹעֵד תֵּשְׁבוּ יוֹמָם וָלַיְלָה. אָמַר לָהֶם מֹשֶׁה לְאַהֲרֹן וּלְבָנָיו, שִׁמְרוּ אֲבֵלוּת שִׁבְעַת יָמִים עַד שֶׁלֹּא יַגִּיעַ בָּכֶם. וּשְׁמַרְתֶּם אֶת מִשְׁמֶרֶת ה', שֶׁכָּךְ שָׁמַר הַקָּדוֹשׁ בָּרוּךְ הוּא שִׁבְעַת יְמֵי אֲבֵלוּת עַד שֶׁלֹּא הֵבִיא אֶת הַמַּבּוּל, כִּבְיָכוֹל. וּמִנַּיִן שֶׁנִּתְאַבֵּל, שֶׁנֶּאֱמַר: וַיִּנָחֵם ה' כִּי עָשָׂה אֶת הָאָדָם וַיִּתְעַצֵּב אֶל לִבּוֹ (בראשית ו, ו). וְאֵין עֲצִיבָה אֶלָּא אֵבֶל, שֶׁנֶּאֱמַר: וַתְּהִי הַתְּשׁוּעָה בַּיּוֹם הַהוּא לְאֵבֶל עַל יִשְׂרָאֵל כִּי אָמַר הָעָם כִּי נֶעֱצַב הַמֶּלֶךְ עַל בְּנוֹ (ש״ב יט, ג). וְכֵן עֶזְרָא אָמַר לְיִשְׂרָאֵל בְּשָׁעָה שֶׁהָיוּ בּוֹכִין אִישׁ אֶל אָחִיו וְאִישׁ אֶל בְּנוֹ, לְכוּ אִכְלוּ מִשְׁמַנִּים וּשְׁתוּ וְגוֹ' וְאַל תֵּעָצְבוּ כִּי חֶדְוַת ה' הִיא מָעֻזְּכֶם (נחמיה ח, י). בְּאוֹתָהּ שָׁעָה שָׁמַר הַקָּדוֹשׁ בָּרוּךְ הוּא שִׁבְעַת יְמֵי הָאֵבֶל עַד שֶׁלֹּא הֵבִיא אֶת הַמַּבּוּל, שֶׁנֶּאֱמַר: וַיְהִי לְשִׁבְעַת הַיָּמִים וּמֵי הַמַּבּוּל הָיוּ עַל הָאָרֶץ (בראשית ז, י). וְכֵן הוּא אוֹמֵר לְאַהֲרֹן וּלְבָנָיו, כְּשֵׁם שֶׁנִּתְאַבֵּל הַקָּדוֹשׁ בָּרוּךְ הוּא עַל עוֹלָמוֹ עַד שֶׁלֹּא הֵבִיא אֶת הַמַּבּוּל, אַף אַתֶּם שִׁמְרוּ אֶת יְמֵי הָאֵבֶל עַד שֶׁלֹּא יַגִּיעַ בָּכֶם. הָיוּ מְשַׁמְּרִים וְלֹא הָיוּ יוֹדְעִים עַל מָה מְשַׁמְּרִים. כְּמַה שֶּׁנֶּאֱמַר: שׁוֹמֵר מִצְוָה לֹא יֵדַע דָּבָר רָע.
Imagine that it's one week to go before the chassunah, and the Rabbi pulls aside the chaosson and kallah and says to them that he has a special task for them to complete in this week before the wedding. He wants them G-d forbid to sit shiva. Can you imagine what the chosson and kallah would think? "The Rabbi has lost his marbles!" is what they would think. Here, it's one week before the grand inauguration of the mishkan, a day of overwhelming simcha, and Moshe comes and tells Aharon and his sons that they need to sit shiva. לֹא יֵדַע דָּבָר רָע they have no idea what bad thing they are sitting shiva for, they have no idea why that have to do this, but they do so anyway.
The flipside is the episode in Sefer Ezra. It's Rosh haShana everyone in shul is crying tears of remorse. Each person is in aveilus for himself, because he married a shiksa and he realizes it's the Yom haDin and he is finished, his life is ruined. Ezra gets up and gives a derasha and tells this guy to go out and party, וְאַל תֵּעָצְבוּ כִּי חֶדְוַת ה' הִיא מָעֻזְּכֶם.
R' Zalman Sorotzkin writes in the Oznayim laTorah that Chazal are trying to tell us that a person can have no idea where he is holding. Am I at a chasunah or am I in the beis aveilus? Sometimes we are on the cusp of tragedy and don't even realize what is around the corner, and sometimes we are tearing kri'ah like our life is ruined and we should instead be dancing. That's a very sobering thought.
Since it's shabbos ha'gadol, maybe we can connect this to leil ha'seder. When it comes to the leil ha'seder, on the one hand we recline like kings, we eat the korban pesach al ha'sova, we recline like kings but on the other hand we eat lechem oni, we eat maror, we eat eggs to remind us of 9 Av. What kind of hodge podge is this? Is it a beis ha'mishteh or beis aveil? According to the Abarbanel that's the meaning of mah nishtana. It's the contrast between haseiba and tibul (which is how the rich would eat) with maror and lechem oni that arouses curiosity. We exist in a twilight world and can't make sense of things. But that's an accurate reflection of life, or at least life as we know it now. The Yaavetz, in his commentary, writes that in our galus we are like a chatzi eved chatzi ben chorin. We can (sometimes) find peace and prosperity in foreign lands, but we know that this is not where we belong. We are in a state of "yachatz," a matzah half full, half empty, unsure of which way things will tilt this year. In Eretz Yisrael, there are missiles flying. The danger is real. But we all sense that it's not time for aveilus, that we are on the cusp of something big, something great just out of reach.