Why was the aron ha'kodesh hidden?

The ramban says (shemos 25:1) that the purpose of the mishkan was to bring serve as a place of the hashroas ha’shechinah:

"כאשר דיבר השם עם ישראל פנים בפנים עשרת הדיברות... כרת עמהם ברית, מעתה הם לו לעם והוא להם לאלקים... והנה הם קדושים ראויים שיהיה בהם מקדש להשרות שכינתו ביניהם  ולכן צוה בתחילה על דבר המשכן שיהיה לו בית בתוכם מקודש לשמו"

“When Hashem spoke to the benei yisroel face-to-face and gave them the aseres hadibros, he made a bris with them. From now on they would be His people and he would be their deity. They now became kodosh and fitting that there should be a mikdash among them in which Hashem would rest his presence. Therefore Hashem first commanded them to build the mishkan so that He would have a house among them dedicated to His name.”

The shechina was present in the mishkan and in the bayis rishon, however the gemara in Yuma (21b) says:

אלו חמשה דברים שהיו בין מקדש ראשון למקדש שני ואלו הן ארון וכפורת וכרובים אש ושכינה ורוח הקודש ואורים ותומים

”These five things were present in the bayis rishon and were not present in the bayis sheni; the aron, the kapores, the keruvim, eish min hashamayim, the shechinah and the urim ve’tumim.”

The shechina and the aron were not present in the bayis sheni. Rav Yitzchok Hutner z”l (Pachad Yitzchok, Yom Kippur, 16) explains the difference this made to the way that things were like in Eretz Yisroel at the time of the bayis rishon and the time of the bayis sheni.

The first difference is that during the bayis rishon the leadership of klal yisroel was in the hands of the neviim, whereas in the times of the bayis sheni, the leadership of klal yisroel was in the hands of the chachamim.

The mishna says:

משֶׁה קִבֵּל תּוֹרָה מִסִּינַי וּמְסָרָהּ לִיהוֹשֻׁעַ וִיהוֹשֻׁעַ לִזְקֵנִים וּזְקֵנִים לִנְבִיאִים וּנְבִיאִים מְסָרוּהָ לְאַנְשֵׁי כְּנֶסֶת הַגְּדוֹלָה

“Moshe accepted the Torah from Sinai and handed it to Yehoshua and Yehoshua to the zekeinim and the zekeinim to the neviim and the neviim handed it to the anshei kenesses hagedola.”

The entire period of the bayis rishon is covered by the period of the neviim, after this time the Torah was handed to the anshei kenesses hagedola and they founded the second beis hamikdash.

Additionally, during the bayis rishon, there was no machlokess in Torah.

Rav Hutner explains that these differences came from the hashpaah of the shechinah that came through the aron which was present in the first  beis hamikdash. Through the shechinah, the neviim were able to communicate with Hashem. Also because of the shechinah, when someone came to learn Torah, it was naturally intuitive to them. Having a machlokess in Torah would have been like having a machlokess whether or not cholent tastes good!

The Aron

King Yoshiyohu hid the aron hakodesh so for the final period of the bayis rishon and for the whole of the bayis sheni the aron was also not present in the kodesh ha’kaddashim. The gemara says that during the time of the second beis hamikdash one of the cohanim saw a lifted flagstone and realised this led to the passageway where the aron had been hidden. Before he could tell his  friends he died supernaturally.

You see from this gemara that it would have been bad for the aron to have been present in the bayis sheni. Why is this so and why was Yoshiyohu gonez the aron?

The possuk says in bereishis:

וַיֹּאמֶר ה' אֱלֹקים הֵן הָאָדָם הָיָה כְּאַחַד מִמֶּנּוּ לָדַעַת טוֹב וָרָע וְעַתָּה פֶּן יִשְׁלַח יָדוֹ וְלָקַח גַּם מֵעֵץ הַחַיִּים וְאָכַל וָחַי לְעֹלָם. וַיְשַׁלְּחֵהוּ ה' אֱלֹקים מִגַּן עֵדֶן לַעֲבֹד אֶת הָאֲדָמָה אֲשֶׁר לֻקַּח מִשָּׁם.

“Hashem said, behold Adam has become like a malach to know good and bad, and now lest he sends out his hand and he takes also from the etz hachaim and he will eat and live forever. And Hashem sent him from Gan Eden to work the land from which he had been taken.”

Why would it would have been bad for Adam to have access to the Etz haChaim after the chet. Surely Hashem would have wanted Adam to eat from the Etz HaChaim and live forever, as it says in davening “ki lo yachpotz bemos hames”?

The possuk days “ve’ato pen yishlach yodo” – “and now in case he sends out his hand.” Why did the possuk need to say “in case he sends out his hand”? Why did the possuk not simply say “in case he eats from the etz hachaim”?

Had Adam eaten from the etz hachaim before the chet, his connection to the etz hachaim would have been internal. His connection to Hashem who is the source of life would have a genuine part of him. However, had he eaten after the chet of the etz ha’daas, his connection to the Etz HaChaim would have been an external, a “shelichus yad”. Hashem sent him from Gan Eden in order to prevent this from happening.

This is the reason that the aron hakodesh was hidden. King Yoshiyohu felt that with the yeridas hadoros the connection to the aron was in danger of becoming external – a shelichus yad – so he hid it. This is why the cohen in the second mikdash was stopped from revealing the place of the aron, in order to prevent the people in the second mikdash falling into the trap of “shelichus yad”.

When the bayis shlishi is rebuilt, the aron will be present in the kodesh ha’kadashim because the yetzer hara that entered us through the chet of the etz hadaas will be killed by Hashem and there will be no concern of shelichus yad as we benefit from ther presence of the shechina.