The calculated distance (air line) between Dayr Ḩāfir and As Salamīyah is approximately 87 miles respectively 140 kilometers.
By car or train, the actual journey to As Salamīyah is certainly longer, as only the direct route (as the crow flies) between Dayr Ḩāfir and As Salamīyah has been calculated here.
Air line (approximately)
140 kilometers
76 nautical miles