Sāṃkhya Kārikā verse 1

duḥkha-trayā-abhighātāt-jijñāsā tat-abhighātake hetau |
dṛṣṭe sā-apārthā cet na-ekāntā-atyantataḥ abhāvāt ||

traya - the threeduḥkha - suffering, pain, sorrowfulabhāva - non-appearance, non-existence

Commentaries and Reflections

TKV Desikachar:

Sāṃkhya will not make sense to those people who have not tried anything.
i.e. Prayer, Mantra, Medicine.”
– TKV Desikachar Madras November 24th 1979 on Sāṃkhya and Yoga

Paul Harvey:

Within and around us is an absence of certainty and permanence.