Dream Harvest is a rare Sorcery card from Lorwyn Eclipsed (ECL), collector number 216. Current market price: $0.38 (foil $0.40), TCGplayer market prices via Scryfall.
Each opponent exiles cards from the top of their library until they have exiled cards with total mana value 5 or greater this way. Until end of turn, you may cast cards exiled this way without paying their mana costs.