Canonical Reference: Dhp 202 Verified Source

“There is no fire like lust, no crime like hatred, no sorrow like the aggregates of clinging, and no happiness higher than inner peace.”

Canonical Pali Original: Natthi rāgasamo aggi, natthi dosasamo kali; Natthi khandhasamā dukkhā, natthi santiparaṃ sukhaṃ.

— Gautam Buddha
The Awakened One, Founder of Dhamma
Historical Setting & Context:

Pali Canon: Dhammapada 15.202 asserting that Santi (peace of mind) is the highest form of happiness.