The calculated distance (air line) between Kharbathā al Mişbāḩ and Gaza is approximately 44 miles respectively 71 kilometers.
By car or train, the actual journey to Gaza is certainly longer, as only the direct route (as the crow flies) between Kharbathā al Mişbāḩ and Gaza has been calculated here.
Air line (approximately)
71 kilometers
39 nautical miles