Buried Treasure [The Lost Caverns of Ixalan]

{T}, Sacrifice Buried Treasure: Add one mana of any color.
{5}, Exile Buried Treasure from your graveyard: Discover 5. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 5 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)