Path of Ancestry is a common Land card from Phyrexia: All Will Be One Commander (ONC), collector number 161. Current market price: $0.31, TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)