Also know as the Tripitaka, or Tipitaka in Pali, it is a foundational text in Buddhism. Sort of like the Old Testament, but with less bear maulings.
This is an excerpt of the Bhaddekaratta, or Auspicious Day, Sutra:
You shouldn’t chase after the past
or place expectations on the future.
What is past
is left behind.
is as yet unreached.
Whatever quality is present
you clearly see right there,
Not taken in,
that’s how you develop the heart.
what should be done today,
for — who knows? — tomorrow
There is no bargaining
with Mortality & his mighty horde.
Whoever lives thus ardently,
both day & night,
has truly had an auspicious day:
so says the Peaceful Sage.