Source: Tasha's Cauldron of Everything

Weapon (flail), rare (requires attunement by a cleric or paladin)

The rounded head of this flail is perforated with tiny holes, arranged in symbols and patterns. The flail counts as a holy symbol for you. When you hit with an attack using this magic flail, the target takes an extra 1d8 radiant damage.

As a bonus action, you can speak the command word to cause the flail to emanate a thin cloud of incense out to 10 feet for 1 minute. At the start of each of your turns, you and any other creatures in the incense each regain 1d4 hit points. This property can't be used again until the next dawn.