Bhagavad Gita 18.37

यत्तदग्रे विषमिव परिणामेऽमृतोपमम्।तत्सुखं सात्त्विकं प्रोक्तमात्मबुद्धिप्रसादजम्॥

yattadagre viṣamiva pariṇāme'mṛtopamam |tatsukhaṃ sāttvikaṃ proktamātmabuddhiprasādajam ||

That which is like poison at first but in the end like nectar—that happiness is declared to be sattvic, born of the purity of one's own mind due to self-realization.

Which at first seems like poison but afterwards acts like nectar—that pleasure is pure, for it is born of wisdom.

Our plain-language meaning of this verse is waiting for scholar review.