Sūtra 2.23

(योग., अव.) इत्थं दृश्यद्रष्टारौ व्याख्याय तत्संयोगं व्याख्यातुमाह।
(Yogasudhākara, Avatārikā ) Ittham dṛśyadraṣṭāru vyākhyāya tat-saṁyogam vyākhyātum āha.
(Yoga. Intro.) Having explained the perceived and the perceiver, states their association.

स्वस्वामिशक्त्यो: स्वरूपोलब्धिहेतु: संयोगः। (सूत्रम्  २.२३)

Sva-swami-śaktyoḥ svarūpa-upalabdhi-hetuḥ sam-yogaḥ. (2.23)

Association of the power of prakṛti and that of puruṣa is the means of seeing the nature of this association (for enjoyment and for liberation).

(योग.) स्वशक्तिर्दृश्यस्वभावः स्वामिशक्तिर्दृक्स्वभाव:। तयोश्चैत्तचेतनत्वेन व्यवस्थितयो: स्वरूपोलब्धिर्भोगापवर्गरूपा। तस्या हेतु: प्रत्ययः संयोगो द्ग्दृश्यभावोsविद्याकृत इति व्याख्यातम्। एवं च यस्याभावे दृग्दृश्ययो: स्वरूपोलब्धिर्न भवति यद्भावे सा भवति स संयोग:2.23.1 कार्यैकोन्नेय इत्युपदिष्टं भवति।

(Yoga.) Sva-śaktiḥ dṛśya-svabhāvaḥ svāmi- śaktiḥ dṛk-svabhāvaḥ. Tayoḥ caitta-cetanatvena vyavasthitayoḥ svrūpa-upalabdhiḥ bhoga- apavarga-rūpā. Tasyāḥ hetuḥ pratyayaḥ sam-yogaḥ dṛk-dṛśya-bhāvaḥ avidyākṛtaḥ iti vyākhyātam. Evam ca yasya abhāve dṛk-dṛśyayoḥ svarūpa-upalabdhiḥ na bhavati yat-bhāve sā bhavati saḥ sam-yogaḥ kāryā ekā unneyaḥ iti upadiṣṭam bhavati.

(Yoga. Com.) Sva-śaktiḥ is the nature of the perceived (the insentient pradhāna/prakṛti  ), svāmi-śaktiḥ is the nature of the perceiver (sentiency puruṣa ).¹ With the insentient (prakṛti) and the sentient (puruṣa) being present (in association), there is enjoyment and liberation (for the perceiver, the human being, puruṣa enshrined in the evolute of prakṛti). The cause of this association, the state of the perceiver and the perceived, is ignorance – this is substance of the aphorism.
And thus, in the absence of which there is no perceiver and perceived, and in its presence, both perceiver and perceived are available.² The elimination of this association is the only task (for the seeker), this is the instruction here (in this yogaśāstra).

This is the audio of our discussion of 2.21.

This aphorism (2.21) was discussed in Yogasūtra group in September 2017.

Sadāśivabrahmendra‘s Yogasudhākara commentary

(योगसुधाकर:)  इत्थं दृश्यद्रष्टारावभिधाय तयो: शेषशेषित्वमभिधातुमाह।
(Yogasudhākaraḥ) Ittham dṛśyadraṣṭāru abhidhāya śeṣaśeṣitvam abhdhatum āha.(Introduction to the sūtra) Thus defining the perceived and the perceiver, to express their object-subject connection he (Patañjali) says:

Sūtra 2.21

तदर्थ एव दृश्यस्यात्मा। (सू. २.२१) Tat-arthaḥ eva dṛśyasa ātmā. (2.21)
The essence of the perceived (world of objects) is only
for the sake of the perceiver (subject). (2.21)

(योगसुधाकर:) दृश्यस्य भोग्यस्यात्मा स्वरूपं द्रष्ट्रर्थमेव न स्वार्थमचेतनत्वादित्यर्थः।
(Yogasudhākaraḥ) dṛśyasya: bhogyasya, atmā: svarūpam, draṣṭṛ-artham eva na sva-artham acetantvāt iti arthaḥ
(Yogasudhākara commentary)The essence of the perceived is for the perceiver; not for its own sake, since it (the perceived, pradhāna) is insentient – this is meaning. 2.21.1

2.21.1 I use the word ‘perceived’ for dṛśya/pradhāna, this includes the phenomenal world as well as the body and mind of the perceiver (who is the seeker/ the liberated person). And, ‘ ‘perceiver’ is for dṛg/draṭṛ/puruṣa ).