Asceticism is a rare Enchantment card from Scars of Mirrodin (SOM), collector number 110. Current market price: $6.56 (foil $35.56), TCGplayer market prices via Scryfall.
Creatures you control have hexproof. {1}{G}: Regenerate target creature. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)