Dream Harvest is a rare Sorcery card from Lorwyn Eclipsed Promos (PECL), collector number 216p. Current market price: $1.23 (foil $1.03), 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.