Yawgmoth's Testament is a rare Sorcery card from Mystery Booster Playtest Cards 2021 (CMB2), collector number 52. Current market price: $0.30, TCGplayer market prices via Scryfall.
Until end of turn, you may play face-up cards you own from exile. If a card would be put into your graveyard or exile from anywhere this turn, put it on the bottom of your library instead.