Another perspective is found here where a critic of Sufism attacks Deobandi and Bahrelvi beliefs regarding Barzakh.
How would the notion of the barzakh affect a poet? Well,
Now in the apprehension of any 'two-ity'- i.e a distinction between two things- the question arises 'what two poles do they define?'- is there a continuum, so to speak, between them? If there is perhaps there is a third word, which hasn't yet occurred to me that is the mot juste.
Another way of approaching the same problem is not to seek to construct the continuum between the two-ity but place oneself in between as the asymptotic limit of both. Contemplating oneself as the divider between the 'two-ity' one may find one's own facticity vanish as one's stable sense of identity is questioned.
To take an example 'kaffir/muslim'- where does the one end and the other begin? One method is to draw up a continuum between 2 opposite idealized conceptions. This process may itself suggest some striking images. The other method is to place oneself in between as the limit case of both conceptions. In Arabi's terminology one now sees with both eyes and imaginally creates (as does Allah when he creates Man with both hands but other beings with but one hand) the new ontological position for yourself to which you are then propelled. This liminal state of barzakh is like the bardo of the Tibetans. Moreover, Mulla Sadr's system begins to look a bit like Heidegger's project. In other words the poet is now in an altered state- one of becoming, one of transformation- rather than one of sitting in judgement or pursuing a craft skill.
The ordinary meaning of barzakh as the Islamic limbo constrains one's use of the term but also informs one's reception of Arabi's theory. The poet, in barzakh, hears his own voice, witnesses his own imaginal projections, as coming- so to speak- from beyond the grave in that space between life and resurrection that- certainly for the school of Ibn Taiymiyya then coming into prominence in India- was nothing but oblivion. The Wahabbis can bring forward plenty of evidence that not even the Prophet can hear or know or do anything till the resurrection. However, Arabi's followers still have a way out. They can simply have a meta-barzakh as the divider/unifier between their position and the Wahabis.
But, just as it turns out that Stoics maintain that their system only works for someone who is already a Sage and is quite unavailing in lesser hands, so has Arabi drawn the ladder up after him, declaring himself the seal of Awlia. In other words, there is a meta-meta-barzakh defined by futility/unity which Ghalib inhabits.
Any evidence that Ghalib knew Arabi's, or Sadr's system? Well, he did read Bedil and Jami. Also maybe his one philosophical essay ?
As a Muslim he must have known the ordinary and popular meaning of barzakh. Indeed, the less philosophy he read the more the tension in his mind between the popular meaning and the esoteric one.
In popular lectures on barzakh, the Masters often quote the line-
hum vahan hai jahan se hum ko bhi
kuch hamari khabar nahin aati
Incidentally this was (the psycho-analyst) Masud Khan's favorite quotation.