The Situation:
The Sword of Wounding has the following magic effect:
Hit points lost to this weapon's damage can be regained only through a short or long rest, rather than by regeneration, magic, or any other means. (DMG, p.207)
If you deal nonlethal damage to a creature it you will knock it out.
When an attacker reduces a creature to 0 hit points with a melee attack, the attacker can knock the creature out. The attacker can make this choice the instant the damage is dealt. The creature falls unconscious and is stable. (PHB, p. 198)
Normally that creature will regain 1 hit point after 1d4 hours (PHB, p. 198), but it cannot regain hit points by anything but a rest.
Question:
Is there a way to bring the creature back on its feet?
My first assumption was that you may be able to take a rest while unconscious, but Miniman pointed out a related Question which may answer that.
Is there anything that allows a unconscious creature to take a (short) rest? Or a spell/item which bypasses the effect of the Sword of Wounding?