[1147] Bhikkhus, these four bases for spiritual power (iddhipāda), when developed and cultivated, are of great fruit and great benefit. And how, bhikkhus, are the four bases for spiritual power developed, how cultivated, so that they are of great fruit and great benefit? Here, bhikkhus, a bhikkhu develops the base for spiritual power endowed with concentration (samādhi) due to desire (chanda) and volitional formations of striving (padhānasaṅkhāra), thinking: "Thus my desire 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 the mind imbued with luminosity.
He develops the base for spiritual power endowed with concentration due to energy … concentration due to mind … concentration due to inquiry (vīmaṃsā) and volitional formations of striving, thinking: "Thus my inquiry 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 that is open and unenveloped, he develops the mind imbued with luminosity.
Bhikkhus, when the four bases for spiritual power are developed thus and cultivated thus, they are of great fruit and great benefit.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.