The Double-Bladed Scimitar can be found in Eberron: Rising from the Last War, page 21.
This magic sword's blade is fashioned from a horn or spine from a crystal dragon. When you hit with an attack roll using this sword, the target takes an extra 1d8 radiant damage.
The sword has 3 charges and regains 1d3 expended charges daily at dawn. When you hit a creature with an attack roll using the sword, you can expend 1 charge to regain a number of hit points equal to the extra radiant damage the sword dealt.
While you're holding the sword, you can use a bonus action to cause it to shed bright light in a 30-foot radius and dim light for an additional 30 feet, to cause it to shed dim light in a 10-foot radius, or to douse the light.
If you attack with a double-bladed scimitar as part of the Attack action on your turn, you can use a bonus action immediately after to make a melee attack with it. This attack deals 1d4 slashing damage on a hit, instead of 2d4.
This weapon requires two hands to use. This property is relevant only when you attack with the weapon, not when you simply hold it.