B.G 18.08
दुःखमित्येव यत्कर्म कायक्लेशभयात् त्यजेत्। स कृत्वा राजसं त्यागं नैव त्यागफलं लभेत् ॥८॥
He who renounces action only because it is suffering, out of fear of bodily discomfort, having performed such passionate 'rajasic' relinquishment, does not indeed obtain the fruits of relinquishment.
Gīta Tātparya 18.08
The suffering mentioned is the mental-suffering, observed when devoid of delusion. The word 'duḥkham' is used for mental suffering alone in ancient sanskrit literature, while 'āyāsaḥ' i.e. exertion, is considered for external physical suffering.
मोहं विना दृष्टदुःखमित्येव। दुःखशब्देन केवलमानसम्। कायक्लेशस्य पृथगुक्तेः।
The suffering mentioned is the one observed when devoid of delusion. The word 'duḥkha' is used to reffer to mental suffering alone. Bodily pain is mentioned separately.
"दुःखं तु मानसं ज्ञेयमायासो बाह्य उच्यते। विशेषस्य विवक्षायामन्यथा सर्वमेव तु॥"
"The word 'duḥkham' i.e. suffering, is recognized as mental, while 'āyāsaḥ' i.e. exertion is considered external. Both are suffering, but a distinction is to be made, especially regarding its intention."
इति शब्दनिर्णये॥
- stated thus in the ancient text Shabdanirṇaya.