The Silmarillion, "Of Aulë and Yavanna"
"Aforetime it was held among the Elves in Middle-earth that dying the Dwarves returned to the earth and the stone of which they were made; yet that is not their own belief. For they say that Aulë the Maker, whom they call Mahal, cares for them, and gathers them to Mandos in halls set apart; and that he declared to their Fathers of old that Ilúvatar will hallow them and give them a place among the Children in the End. Then their part shall be to serve Aulë and to aid him in the remaking of Arda after the Last Battle."
::::::
"Dear? Why are there dwarves in the kitchen?" Yavanna asked, leaning against the door of Aule's workshop.
Aule looked up and blinked at her. "In the kitchen... Oh, I suppose they must have gotten hungry."
"Why are there dwarves *here*, in Valinor?"
"Because they died!" Aule stared at his spouse. "I couldn't just let their spirits wander! That wouldn't be right!"
Yavanna sighed. Her husband was a dear, but he simply didn't think at times. "Why do they need to be here? Couldn't we send them to Mandos? The house isn't really big enough for them."
"Oh. Yes, that could work."
"Good. I'll talk to Namo about it."
