[382] The cultivation of equanimity is the middle of the path of Arahantship (arahattamagga). How many are the characteristics of the middle? The middle has three characteristics: one looks on with equanimity at the purified mind (citta); one looks on with equanimity at [the mind] that has entered upon serenity (samatha); one looks on with equanimity at the establishment of unity (ekattupaṭṭhāna). In that one looks on with equanimity at the purified mind, and looks on with equanimity at that which has entered upon serenity, and looks on with equanimity at the establishment of unity — therefore it is said that the path of Arahantship is good in the middle and endowed with the characteristics.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.