Atītaṃ nānvāgameyya,
nappaṭikaṅkhe anāgataṃ;
yadatītaṃ pahīnaṃ taṃ,
appattañca anāgataṃ
The past should not be followed after,
and the future not desired;
what is past is dead and gone,
and the future is yet to come.
Majjhima Nikāya 3.272
Gemstones of the Good Dhamma,
compiled and translated by Ven. S. Dhammika