Samkhya Karika 55

तत्र जरामरणकृतं दुःखं प्राप्नोति चेतनः पुरुषः ।
लिङ्गस्याविनिवृत्तेः, तस्माद् दुःखं स्वभावेन ॥ ५५ ॥

tatra jarāmaraṇakṛtaṁ duḥkhaṁ prāpnoti cetanaḥ puruṣaḥ ।
liṅgasyāvinivṛtteḥ, tasmād duḥkhaṁ svabhāvena ॥ 55 ॥

Tatra (there, in the three worlds mentioned in the previous sutra); jarā=old age; maraṇa=death; kṛtaṁ=caused by; duḥkhaṁ=suffering; prāpnoti=experiences; cetanaḥ=conscious; puruṣaḥ=Purusha; liṅgasya=of the subtle body; āvinivṛtteḥ=until deliverance (from the subtle body); tasmāt=therefore; duḥkhaṁ=suffering; svabhāvena=natural

Therein (in the three worlds), the conscious Purusha suffers pain born of old age and death until it is released from the subtle body. Thus, pain is natural in this creation.

The word “tatra (therein)” refers to the three worlds mentioned in the previous two sutras – higher (divine), middle (human), and the lower (animal etc.) worlds. Purusha, which is pure consciousness (chetanā), not realizing its true identity as being separate from Prakriti, gets identified with the buddhi (intellect). As such, the suffering caused by old age and death is also experienced by Purusha.

The word “liṅgasyāvinivṛtteḥ” can be interpreted in two different ways:

1. liṅgasya +āvinivṛtteḥ: suffering continues until Purusha is released from the subtle body.
2. liṅgasya+avinivṛtteḥ: suffering continues because Purusha is not released from the subtle body.

Mishra uses the first interpretation in his main discussion. However, as a footnote, he mentions the second one as an alternative interpretation.

Gaudapada goes with the first interpretation only. He also makes the statement that the suffering is experienced by Purusha alone and not by Prakriti or any of its evolutes like buddhi etc. This seems to contradict our normal understanding that all experiences are happening at the level of buddhi etc. Purusha experiences suffering etc. only because, due to ignorance, he does not know his true identity and remains identified with the buddhi.

The last part of the second line reiterates that as a result of Purusha not being liberated from its bondage with Prakriti,  suffering in life is natural. This is similar to what Patanjali states in the yoga sutras (sutra 2.15¹):

“To one of discrimination, everything is painful indeed, due to its consequences: the anxiety and fear over losing what is gained; the resulting impressions left in the mind to create renewed cravings; and the constant conflict among the three gunas and the vrittis, which control the mind.”

This sutra esentially is the very essence of Samkhya philosophy, emphasizing that the path to final liberation (called Kaivalya) is the realization of separation of Purusha and Prakriti.

Note 1: (sutra 2.15)

परिणामतापसंस्कारदुःखैर्गुणवृत्तिविरोधाच्च दुःखमेव सर्वं विवेकिनः॥१५॥ pariṇāma tāpa saṁskāra duḥkhaiḥ guṇa-vr̥tti-virodhācca duḥkham-eva sarvaṁ vivekinaḥ ॥15॥