When Arcane Sanctuary enters the battlefield, you may search your library for an Instant or Sorcery card, reveal it, then shuffle your library and put that card on top of it.

{T}, Pay 1 life: Add one mana of any color to your mana pool. If that mana is spent on an Instant or Sorcery spell, that spell gains "If this spell doesn't resolve, put it into its owner's hand instead of into that player's graveyard."

{4}, {T}, Sacrifice Arcane Sanctuary: Take an extra turn after this one. Skip your next untap step.