Madhvaon Brahma Sūtra 3.1.19

" In the state of being animals, and in the temporary hell, there is said to be but slight touch of pleasure; but those ’who are plunged in the hell of darkness have no pleasure whatever" (Bhavishyat) (Parvan). This is also settled from the observation of the world. By the particle ‘ Cha ’ (and) the Sutrakara intimates that the observation of the world is also one corroborated by Smriti. It is said in the Brahmapurana thus, “Just US a king may not bear to see the least suffering in his strictest friend or to see the least pleasure in the bitterest (most abhorred) enemy, so does the Supreme Dord.”