we say: Verily, the boundary of recognition demanded of the believer is the recognition of that hairline-receding Form (al-Ṣūrah al-Anza‘iyyah), according to the statement of our Master Abu Sa‘id, Allah sanctified his secret:

"Nothing was intended or relied upon except the recognition of the Form,"

...because it is impossible for anyone to recognize the core essence (kunh) or the quiddity (māhiyyah) of the Essence. That is the unassailable Hiddenness (al-ghayb al-manī‘) and the unknown Boundary, which Allah, glorified is He, has not demanded any of His creation to recognize.

This is exactly as the Master, glorified is his glory, said:

“Verily, behind Me is an Other besides Me, and you are not obligated to recognize that Other.”

In his commentary on this tradition, the author of Ḥujjat al-‘Ārif, Allah sanctified his secret, says:

"The 'behind' here signifies the Inward reality (al-bāṭin) of which I am the Outward manifestation. By His saying: 'an Other besides Me,' He intended that which is other than My outward manifestation which you plainly witness.