The Vatican says Pope Francis has presented a decree to Mexican indigenous peoples approving the use of the Aztec language Nahuatl in Mass.  Pope Francis celebrated a Mass in three other indigenous languages Monday during a visit to the southern state of Chiapas — Tzeltal, Tzotzil and Chol. Official approval for those languages is still pending, but the Vatican spokesman, the Rev. Federico Lombardi, said the fact that Francis celebrated a Mass in which readings, prayers and the Gospel were read out in those languages is a sign that they are allowed to be used.