Go to Shadowfang Keep and obtain the Commander's Holy Symbol from Commander Springvale, 5 crates of Moonsteel Ingots, and 5 Deathless Sinew.
I have been watching your progress, <name>, and I can only conclude that the Light shines brightly upon you. You are becoming an exemplary <class>.
To honor your dedication, King Wrynn has commissioned the royal armorer to forge a special weapon.
The materials to make your weapon are unique, and only found in the cursed Shadowfang Keep in Silverpine Forest. Travel there and recover the holy symbol of Commander Springvale, a supply of moonsteel ingots, and sinew from the ghouls and geists infesting the keep.