[36] "But who, venerable sir, clings?"
"The question is not a fitting one," the Blessed One said. "I do not say 'one clings.' If I were to say 'one clings,' then that would be a fitting question: 'But who, venerable sir, clings?' But I do not speak thus. When I do not speak thus, if anyone should ask me: 'With what as condition, venerable sir, is there clinging (upādāna)?' — that is a fitting question. There the fitting answer is: 'With craving (taṇhā) as condition, clinging; with clinging as condition, existence (bhava)' … Such is the origin of this whole mass of suffering (dukkha)."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.