What is "non-abidance"

In Buddhism, especially the Chan ( Zen) traditions, non-abidance (in Sanskrit: apratiṣṭhita, with the a- prefix, ‘unlimited’, ‘unlocalized’) is the practice of avoiding mental constructs during daily life. That is, other than while engaged in meditation ( zazen).

Some schools of Buddhism, especially the Mahāyāna, consider apratisthita- nirvana ("non-abiding cessation") to be the highest form of Buddhahood, more profound than pratiṣṭhita-nirvāṇa, the ‘localized’, lesser form.