“Do not dwell in the past, do not dream of the future, concentrate the mind on the present moment. Today's effort must be made today.”
Canonical Pali Original: Atītaṃ nānvāgameyya, nappaṭikaṅkhe anāgataṃ; Yadātītaṃ pahīnaṃ taṃ, appattañca anāgataṃ; Paccuppannañca yo dhammaṃ, tattha tattha vipassati.
— Gautam Buddha
The Awakened One, Founder of Dhamma
Delivered at Jetavana monastery in Savatthi, expounding the core vipassana practice of present-moment awareness.