evening meal, supper, cooked food
飧 centers on the evening meal: supper, or more broadly cooked food eaten at that time.
飧 combines 夕 (evening) and 食 (food/eat), directly suggesting the evening meal. The historical development is straightforward.
夕 is evening, and 食 is food. Picture the evening meal being served: 飧 is supper.
For ソン, imagine a son helping prepare the evening meal: son -> ソン, and the son sets the table for supper.