[77] Bhikkhus, there are these four inconceivable matters (acinteyya) that should not be thought about; one thinking about them would partake of madness and vexation. Which four? The Buddha-range of the Buddhas (buddhavisaya), bhikkhus, is inconceivable and should not be thought about; one thinking about it would partake of madness and vexation. The range of jhāna of one who meditates (jhānavisaya), bhikkhus, is inconceivable and should not be thought about; one thinking about it would partake of madness and vexation. The result of kamma (kammavipāka), bhikkhus, is inconceivable and should not be thought about; one thinking about it would partake of madness and vexation. Speculation about the world (lokacintā), bhikkhus, is inconceivable and should not be thought about; one thinking about it would partake of madness and vexation. These indeed, bhikkhus, are the four inconceivable matters that should not be thought about; one thinking about them would partake of madness and vexation.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.