Kasbah? Casbah? Qasbah?

Casbah, the traditional transliterational spelling, means the inner-city warren of alleyways in Arab urban locales, also describing the old part of a city.

So why is it spelled differently in David Grossman's newly translated novel here:-

Ofer seemed to want, at the very last minute, to fill in what he had left out, and he told her hurriedly about the pillbox he’d lived in for four months, facing the northern neighborhood of Jenin, and how every morning at five he used to open the gate in the fence around the pillbox and make sure the Palestinians hadn’t booby-trapped it overnight. “You just walked over there like that, alone?” she asked. “Usually someone from the pillbox would cover me—I mean, if anyone was awake.” She wanted to ask more but her throat was dry, and Ofer shrugged and said in an elderly Palestinian man’s voice, “Kulo min Allah“—it’s all from God. She whispered, “I didn’t know,” and he laughed without any bitterness, as if he had understood that she could not be expected to know, and he told her about the kasbah in Nablus, which he said was the most interesting of all the kasbahs, the most ancient. “There are houses there from the Roman era and houses built like bridges over alleyways, and underneath the whole city there’s an aqueduct that goes from east to west, with canals and tunnels running in all directions, and the fugitives live there because they know we’ll never dare follow them down.”

Maybe the English spelling derived from the Spanish alcazaba?

- - -