Firemind's Foresight is a rare Instant card from Duel Decks: Mind vs. Might (DDS), collector number 21. Current market price: $0.32, TCGplayer market prices via Scryfall.
Search your library for an instant card with mana value 3, reveal it, and put it into your hand. Then repeat this process for instant cards with mana values 2 and 1. Then shuffle.