קבלה אויף דברים 10:2

Let me therefore transmit a general principal to you. That is, the Tablets of the Covenant (Luchot HaBrit) were placed in the Ark (Aron). This is as stated,²⁸⁰Deuteronomy 10:2 “And you shall place them in the Ark.” Now, the written Torah is expounded upon solely by means of the Oral Torah. This is because the Oral Torah (Torah SheBa’al Peh) is the Sanctuary (Heichal) of the Written Torah (Torah SheB’Khtav). The sign by which to remember this, is the fact that the title Lord-Adona”y-אדנ״י-65 is the Sanctuary-Heichal-היכל-65 of the Name HaShem-יהו״ה.