[1239] "And what, bhikkhus, is the development (bhāvanā) of the bases for spiritual power (iddhipāda)? Here, bhikkhus, a bhikkhu develops the basis for spiritual power that possesses concentration (samādhi) due to desire (chanda) and volitional formations of striving (padhānasaṅkhāra). He develops the basis for spiritual power that possesses concentration due to energy … concentration due to mind (citta) … concentration due to investigation (vīmaṃsā) and volitional formations of striving. This, bhikkhus, is called the development of the bases for spiritual power."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.