Bhagavad Gita · Chapter 18: Freedom through Renunciation
Bhagavad Gita 18.37
यत्तदग्रे विषमिव परिणामेऽमृतोपमम् ।
तत्सुखं सात्त्विकं प्रोक्तमात्मबुद्धिप्रसादजम् ॥
yattadagre viṣamiva pariṇāme'mṛtopamam | tatsukhaṃ sāttvikaṃ proktamātmabuddhiprasādajam ||
which is like poison at first but like nectar in the end: that happiness, born of the clear understanding of the self, is said to be of clarity.
Modern context
Sattvic happiness is like poison at first but nectar in the end. This is one of the most practical teachings in the Gita. Exercise, study, saving money, honest conversations: they are hard at the start and rewarding later. Real joy often begins with discomfort. If something feels difficult now but leads to clarity and peace, it is probably worth it.