זוהר שמות — דף רלד ע”א

The secret of the Ark lies in the calculation of what it takes, receives, and contains. Its measurements are two and a half cubits long, one and a half cubits wide and tall, receiving from the two supernal sides. The cover is the secret of the Shekhinah that rests upon the Ark in the supernal mystery and is nourished by it. The two Cherubim upon the cover are the secret of perfect union and prophetic Presence, merging together in the Holy of Holies.