זוהר בראשית — דף רנ ע”ב

The Community of Israel is called the cup of blessing, and right and left are needed to receive it and fill it with wine. Here in the cave was revealed the secret of the holy Chariot: the cup of blessing must be received with the right hand. The secret of the matter is that blessings come from masculine and feminine, and the cup of blessing is the secret of Unification. In this cave supernal secrets were revealed to Rabbi Shimon, and the secret of the holy Chariot is the Unification of the upper and lower.