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 watched your training, <name>. Yours is the path of an exemplary Sunwalker, a brave defender of the Horde and a follower of our ways.
As a reward for your dedication, the warchief has commissioned his personal smith to forge a special weapon.
The cursed Shadowfang Keep in Silverpine Forest is the only place to get the materials you'll need. 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.