This is symbolized by the "Outward of the Wall" mentioned by the Almighty in Surat al-Hadid:

{So a wall will be placed between them with a door, its interior (bāṭinuhu) containing mercy, but its exterior (ẓāhiruhu) facing torment}. (Al-Hadid: 13).

That is to say: Mercy comes from the belief in the Esoteric Sciences, while Torment comes from the belief in the Exoteric Sciences. The "Wall" refers to those outward forms which the Almighty made as a veil and a guide to the Persons (Ashkhāṣ) and the esoteric knowledges.

Abdullah ibn Saba and his brothers—peace be upon them—pointed to this [meaning] regarding the Commander of the Faithful, as reported in the fifth part of the first volume of Sharḥ Nahj al-Balāghah by Ibn Abi al-Hadid, on the authority of Abu al-Abbas, from Muhammad bin Salman bin Habib al-Massisi, from Ali bin Muhammad al-Nawfali, from his father and his sheikhs:

Ali passed by Abdullah ibn Saba and his brothers while they were eating during the day in the month of Ramadan.

He said: "Are you travelers or ill?" They said: "Neither." He said: "Are you from the People of the Book?" They said: "No." He said: "Then what is the matter with eating during the day in Ramadan?" They said: "Anta Anta" (You are You).