As an action you touch one melee weapon, or one piece of ranged ammunition, and imbue it with a spell of 3rd level or lower that has a range of Touch. You must have the spell prepared, and you must have the required spell slot available, which is expended in the process. That spell is held in the weapon for a number of rounds equal to your spellcasting ability modifier, or until the weapon is used to make an attack against a creature or object. On a successful attack the weapon deals its usual damage and the spell is cast on the target of the attack. Once the spell has been transferred to the target, if the spell requires Concentration, you must concentrate on it as usual, or it ceases to function. If the target is a creature, any saving throw allowed by the spell is made with disadvantage if the creature took damage from the weapon attack. You may use this feat a number of times equal to half your level rounded up, after which you must complete a long rest before regaining its use.
Prerequisite: Ability to cast spells.