The calculated distance (air line) between Dayr Abū Ḑa‘īf and Gaza is approximately 84 miles respectively 136 kilometers.
By car or train, the actual journey to Gaza is certainly longer, as only the direct route (as the crow flies) between Dayr Abū Ḑa‘īf and Gaza has been calculated here.
Air line (approximately)
136 kilometers
73 nautical miles