Larian Studios Forums Baldur's Gate III Baldur's Gate III - Help Tips & Tricks Uber gear thread. Spoilers, obviously.

Whispering Promise actually is sold by Volo initially...you have to hit the trade icon in the lower left as there is no dialogue option to trade with him. I did not buy it from him in Act 1 and then in Act 2 it was on the Zhent short merchant (who you can easily aggro/kill in the Goblin camp in Act 1) in Moonrise Towers.