[If one says,] ‘This ox shall be an olah offering,’ [or] ‘this house shall be an offering’ — [if] the ox died or the house collapsed, he is not obligated to pay. [But if he says,] ‘I take upon myself [to give] the worth of this ox as an olah offering,’ or ‘I take upon myself [to give] the worth of this house as an offering’ — [if] the ox died or the house collapsed, he is obligated to pay.