Source: The Book of Many Things

Staff, rare (requires attunement by a Cleric, Druid, or Wizard)

Veins of sunstone run through this wooden staff. This staff can be wielded as a magic quarterstaff that grants a +1 bonus to attack and damage rolls made with it. When you hit with an attack roll using this staff, the target takes an extra 1d8 fire damage.

Solar Focus. You can use the staff as a spellcasting focus. While holding the staff, you can reroll a number of damage dice up to your proficiency bonus when you use a spell slot to cast a spell that deals fire or radiant damage. You must use the new rolls. Once this property is used, it can’t be used again until the next dawn.

Sunny Glow. As a bonus action, you can cause the staff to glow with sunlight. While glowing, the staff sheds bright light in a 15-foot radius and dim light for an additional 15 feet. The light lasts until you use another bonus action to extinguish it.