The Cleric's Vestments are found in the Lich Outpost in Baldur's Gate: Siege of Dragonspear.
Description[]
| “ | These dark red and green robes are of a simple dwarven design, but made with material of the highest quality and care. The sleeves and fringe end in gold trim, and the lining is a soft and luxurious silk as is traditional for dwarven noble wear. | ” |