This spell is originally from the old sourcebook "Bastion of Faith" by Bruce Cordell.
While it was at the beginning allowed only to the Clerics of Hextor from Greyhawk setting, now it's known and used by many faiths in several worlds and planes
4th-level trasmutation spell
Casting Time: 1 action
Components: V, S, M (two human bones)
Duration: 1 minute
You create two additional arms on your torso. They can normally take, hold and use objects and weapons.
On your turn:
- You can take the Use an Object action as a bonus action.
- If you take the Attack action you make two additional attacks, and you add your proficiency bonus to attack rolls if they're holding weapons your proficient with.
- If you make a melee spell attack, you have advantage on that attack roll.
On an opportunity attack you make two attacks instead of one.
Any armor or clothing you wear is magically altered to allow the new limbs and they revert to their new form immediately at the end of the spell.
Weapons or items carried immediately drop at the end of the spell.
At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the arms are four, on your turn you make four additionaly attack rolls if you take the Attack action and you make three attacks on an opportunity attack.