By playing Steward of the Harvest, you create the vital bridge needed for this loop, stealing the text boxes of land cards in your graveyard so your creatures inherit their land-based activated abilities—most importantly, the explosive mana-producing capability of Gaea's Cradle. Equipping that creature with Sword of the Paruns gives you a reliable way to mechanically untap it by paying three mana, which is easily covered when Gaea's Cradle generates an abundance of green mana for each creature you control. Once the loop is humming, Sword of the Paruns conveniently pumps your entire board's stats depending on whether your creatures are tapped or untapped, yielding infinite green mana and infinite untaps to secure your victory.