Nārada’s Protection of Kayādhu and Prahlāda’s Womb-Instructions: Ātma-tattva and the Path of Bhakti
सुखाय दु:खमोक्षाय सङ्कल्प इह कर्मिण: । सदाप्नोतीहया दु:खमनीहाया: सुखावृत: ॥ ४२ ॥
sukhāya duḥkha-mokṣāya saṅkalpa iha karmiṇaḥ sadāpnotīhayā duḥkham anīhāyāḥ sukhāvṛtaḥ
In this material world, every materialist desires to achieve happiness and diminish his distress, and therefore he acts accordingly. Actually, however, one is happy as long as one does not endeavor for happiness; as soon as one begins his activities for happiness, his conditions of distress begin.
Every conditioned soul is bound by the laws of material nature, as described in Bhagavad-gītā ( prakṛteḥ kriyamāṇāni guṇaiḥ karmāṇi sarvaśaḥ ). Everyone has achieved a certain type of body given by material nature according to the instructions of the Supreme Personality of Godhead.
This verse says that the karmī plans for happiness and relief from distress, but anxious striving (īhā) repeatedly brings suffering instead of peace.
Prahlāda was instructing his asura schoolmates that material planning cannot secure real happiness; freedom from agitation and turning toward higher spiritual life is the wiser course.
Do your duties responsibly, but drop obsession and anxious over-planning for enjoyment; cultivate inner steadiness and spiritual purpose so the mind is not driven by fear and craving.