Healing Salve (Warcraft III)

Regenerates target unit's hit points by 400 over 45 seconds when used.

Source
Kael, Lady Vashj and Illidan can find one in Gates of the Abyss, chapter 5 of the Frozen Throne alliance campaign, Curse of the Blood Elves.

Illidan, Kael, Lady Vashj and Akama can find one in Lord of Outland, chapter 6 of that campaign.