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SB 3.26.8

kārya-kāraṇa-kartṛtve
 kāraṇaṁ prakṛtiṁ viduḥ
bhoktṛtve sukha-duḥkhānāṁ
 puruṣaṁ prakṛteḥ param
Synonyms: 
kārya — the body; kāraṇa — the senses; kartṛtve — regarding the demigods; kāraṇam — the cause; prakṛtim — material nature; viduḥ — the learned understand; bhoktṛtve — regarding the perception; sukha — of happiness; duḥkhānām — and of distress; puruṣam — the spirit soul; prakṛteḥ — to material nature; param — transcendental.
Translation: 
The cause of the conditioned soul’s material body and senses, and the senses’ presiding deities, the demigods, is the material nature. This is understood by learned men. The feelings of happiness and distress of the soul, who is transcendental by nature, are caused by the spirit soul himself.
Purport: 

In Bhagavad-gītā it is said that when the Lord descends to this material world, He comes as a person by His own energy, ātma-māyā. He is not forced by any superior energy. He comes by His own will, and this can be called His pastime, or līlā. But here it is clearly stated that the conditioned soul is forced to take a certain type of body and senses under the three modes of material nature. That body is not received according to his own choice. In other words, a conditioned soul has no free choice; he has to accept a certain type of body according to his karma. But when there are bodily reactions as felt in happiness and distress, it is to be understood that the cause is the spirit soul himself. If he so desires, the spirit soul can change this conditional life of dualities by choosing to serve Kṛṣṇa. The living entity is the cause of his own suffering, but he can also be the cause of his eternal happiness. When he wants to engage in Kṛṣṇa consciousness, a suitable body is offered to him by the internal potency, the spiritual energy of the Lord, and when he wants to satisfy his senses, a material body is offered. Thus it is his free choice to accept a spiritual body or a material body, but once the body is accepted he has to enjoy or suffer the consequences. The Māyāvādī philosopher’s presentation is that the living entity enjoys his pastimes by accepting the body of a hog. This theory is not acceptable, however, because the word “pastime” implies voluntary acceptance for enjoyment. Therefore this interpretation is most misleading. When there is enforced acceptance for suffering, it is not a pastime. The Lord’s pastimes and the conditioned living entity’s acceptance of karmic reaction are not on the same level.