The Torah states at the end of this week’s parshah that when Bnei Yisrael travel in the midbar, the kohanim must take the paroches and cover the aron with it. Other items from the Mishkan also had to be covered.
This was necessary so that the levi’im wouldn’t accidentally touch one of the vessels or look at the aron while it was being inserted into its place and die as a result.
Rishonim debate whether the prohibitions against looking at the aron and touching holy vessels are included among the 613 mitzvos. Rabbeinu Sadya Gaon (Lavim 212), the Behag, and the Yereim (329) believe they are while the Rambam and Sefer HaChinuch believe they are not. (This does not mean that looking at the aron or touching the vessels is okay according to these Rishonim; many acts are prohibited mi’de’oraisa but not included among the 613 mitzvos.)
The Rambam doesn’t include these prohibitions because he maintains that they only applied while Bnei Yisrael were traveling in the midbar, and any prohibition that does not apply to every generation cannot be counted among the 613 mitzvos (as the Rambam writes in his third shoresh).
The Rambam adds that although the Gemara (Sanhedrin 82b) derives from this lav that one who steals a holy vessel may be killed by a kana’i, the prohibition is nevertheless not explicit in the pasuk. Only mitzvos that are clearly stated in the pasuk may be counted as one of the 613 mitzvos.
The Gemara (Yoma 54a) says that when Klal Yisrael were oleh regel, the kohanim would remove the paroches and allow them to see the aron and the keruvim embracing in order to show them that Hashem loves them. The Gemara wonders why this was permitted. It explains that the Jews in the desert were like a kalah who is modest around her fiancé in her parents’ house. Rashi explains that in the midbar, Klal Yisrael were still not “comfortable” with the shechinah; therefore, they were not allowed to see the aron. But later on, they were permitted to look.
However, the Gemara then reports a story that implies that Beni Yisrael were never allowed to look. A kohen in the time of the second Beis HaMikdash noticed a strange floor and wished to inform his peers of this. But he died before he could tell anyone. The Gemara explains that the aron was buried there and states that we can infer from this story that the prohibition against looking at the aron applies even after the Bnei Yisrael left the midbar, which is why the kohen died.
So were Jews who lived after the dor hamidbar allowed to look or not? The Gemara answer: The prohibition applies in every generation. The only exception was the era of the first Beis Hamikdash. In that era, Jews were allowed to see the keruvim embracing
Rav Yerucham Fishel Perlow, in his commentary on Rabbeinu Sadya Gaon, asks how the Rambam can exclude this prohibition base on the theory that it only applied to the generation of the midbar when the Gemara, as we’ve just seen, explicitly states that it applies to all generations (with the exception of the era of the first Beis Hamikdash).
Rav Perlow suggests that the Rambam based his position on a different Gemara – Sota 35a – that disagrees with the Gemara in Yoma. Shmuel Aleph 6:19 records that Hashem killed some of Beis Shemesh’s inhabitants because they “looked at the aron” when the Philistines returned it to their city. Examining this story, the Gemara in Sotah asks why they deserved death for looking at the aron. Rabbi Avahu and Rabbi Elazar answer that they acted in a disrespectful manner.