As part of the action used to cast this spell, you must choose a melee weapon to be used as the focus of the casting, otherwise the spell fails. You whisk the weapon you are wielding in the air, gathering a sharp wind along the length of the weapon. The wielded weapon gains the Reach property and deals an additional 1d6 slashing damage for the duration. 

At Higher Levels: When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.