2nd-Level Conjuration
You fill the air with spinning daggers in a cube 5 feet on each side, centered on a point you choose within range. A creature takes 4d4 slashing damage when it enters the spell's area for the first time on a turn or starts its turn there.
When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 2d4 for each slot level above 2nd.
Player's Handbook (2014), p. 222