[1140] He develops the basis for spiritual power (iddhipāda) endowed with concentration (samādhi) due to investigation (vīmaṃsā) and with volitional formations of striving (padhānasaṅkhāra), thinking: "Thus my investigation will be neither too slack nor too strained; it will be neither constricted internally nor distracted externally." And he dwells perceiving after and before: "As before, so after; as after, so before; as below, so above; as above, so below; as by day, so by night; as by night, so by day." Thus, with a mind (citta) that is open and unenveloped, he develops a mind imbued with luminosity.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.