Sigarda's Splendor is a rare Enchantment card from Innistrad: Midnight Hunt Promos (PMID), collector number 33s. Current market price: — (foil $1.37), TCGplayer market prices via Scryfall.
As this enchantment enters, note your life total. At the beginning of your upkeep, draw a card if your life total is greater than or equal to the last noted life total for this enchantment. Then note your life total. Whenever you cast a white spell, you gain 1 life.