The calculated distance (air line) between Sīlat al Ḩārithīyah and Gaza is approximately 83 miles respectively 133 kilometers.
By car or train, the actual journey to Gaza is certainly longer, as only the direct route (as the crow flies) between Sīlat al Ḩārithīyah and Gaza has been calculated here.
Air line (approximately)
133 kilometers
72 nautical miles