The Dwarves are often thought to be a greedy and miserly race, but there are times when they will give rewards to those who have genuinely earned them.
(OOC-I added the names of all those who did submissions but only mine has shown up, for some reason. The others are the following; axlerowes, Echomirage, Ancient Gamer ,Dossta , Pariah.)
When you sleep, your soul briefly returns to the place where it was created/goes to when it dies, and seeks nourishment. Everybody's soul is created with a little link (or you could say a greater entity calls it back) to that place so that it can return easily, but upon death, the soul returns via that and annihilates the link as if returns.
Also, as an added thingy, you could say the entity supplying the link, or residue of the links themselves, (whichever) is the source of all arcane power.