Hall of Oracles is a rare Land card from Strixhaven: School of Mages (STX), collector number 267. Current market price: $0.43 (foil $0.44), TCGplayer market prices via Scryfall.
{T}: Add {C}. {1}, {T}: Add one mana of any color. {T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.