Leyline of Abundance is a rare Enchantment card from Wilds of Eldraine: Enchanting Tales (WOT), collector number 56. Current market price: $2.48 (foil $3.37), TCGplayer market prices via Scryfall.
If this card is in your opening hand, you may begin the game with it on the battlefield. Whenever you tap a creature for mana, add an additional {G}. {6}{G}{G}: Put a +1/+1 counter on each creature you control.