The story "Zaabalawi" by Naguib Mahfouz can be interpreted as: a. a spiritual quest b. a portrait of mental illness/obsession...

While all of these answers have some validity, the most convincing answer is that the story "Zaabalawi" can be interpreted as answer A, a spiritual quest. The narrator is "afflicted by that illness for which no one possesses a remedy." He is "overcome with despair," so he goes in search of Sheikh Zaabalawi, a saint who takes away people's troubles. 

Most people the narrator encounters are disinterested in finding Zaabalawi. The lawyer, named Sheikh Qamar,...

While all of these answers have some validity, the most convincing answer is that the story "Zaabalawi" can be interpreted as answer A, a spiritual quest. The narrator is "afflicted by that illness for which no one possesses a remedy." He is "overcome with despair," so he goes in search of Sheikh Zaabalawi, a saint who takes away people's troubles. 

Most people the narrator encounters are disinterested in finding Zaabalawi. The lawyer, named Sheikh Qamar, does not even recall the saint, as the lawyer lives a life of material luxury that occupies his mind. The shopkeeper, who sells books of theology and mysticism from the entrance of a dilapidated house that is filled with garbage, is too tired and careworn to search for the saint. The sheikh of the district approaches the task of finding the saint in a systematic way that deprives it of its spiritual quality. He says he has been too preoccupied with "the cares of the world" to think about the saint lately. The only people who seem interested in finding Zaabalawi are the calligrapher and musician, who are both spiritual men.

When the narrator goes to a bar in search of the saint and gets drunk, he has a beautiful and serene dream, and when he wakes, he hears that Zaabalawi has been with him. In his state of drunkenness, he has entered a spiritual state in which the saint can visit him. He vows to continue to search for Zaabalawi at the end of the story. It is clear the saint is not a material presence but a spiritual presence who only visits people who are spiritual in nature and who are carried away, as the narrator was by drink, into a state of ecstasy or mysticism. The other characters are too focused on earthly matters to find the saint, but the narrator, carried into the spiritual realm, finds his saint. The tale is one of a spiritual quest.