Rain of Riches is a rare Enchantment card from New Capenna Commander (NCC), collector number 150. Current market price: $24.34, TCGplayer market prices via Scryfall.
When this enchantment enters, create two Treasure tokens. The first spell you cast each turn that mana from a Treasure was spent to cast has cascade. (When you cast the spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)