Hour of Promise is a rare Sorcery card from Hour of Devastation (HOU), collector number 120. Current market price: $0.26 (foil $0.85), TCGplayer market prices via Scryfall.
Search your library for up to two land cards, put them onto the battlefield tapped, then shuffle. Then if you control three or more Deserts, create two 2/2 black Zombie creature tokens.