Emit Force

A ball of force expands outward from you. Each creature of your choice in a 15ft sphere must make a STR saving throw. On a failed save, a creature takes 4d6 force damage, is thrown 15ft away from you, and is knocked prone. A creature takes half as much on a successful save and is only pushed to the edge of the 15ft sphere.

When a creature fails it's save and is pushed into a stationary object it takes an additional 2d6 bludgeoning damage. 

When a creature would be pushed beyond a ledge, If it succeeded it's saving throw it is pushed only to the ledge. 

When you cast this spell at 3rd level or higher, the damage increases by 1d6 for each slot level above 3rd