You can reverse time by perfectly speaking words as if they were recorded and played backwards. The only caveat is that there's a threshold before this becomes truly useful. You must speak in reverse for at least 17 hours before you can turn back time a single hour. However, once you pass the 17-hour threshold, the amount of time you can undo increases exponentially.
This is why all religious chants appear to be in a different language and take so long to complete. Chanting monks are actively trying to unwind history and restart humanity in a more primitive era.