Suññatavāra

Abhidhammapiṭaka · Dhammasaṅgaṇī · Vol. 34 · Section 398

[398] What on that occasion is the aggregate of volitional formations (saṅkhārakkhandha)? Contact (phassa), volition (cetanā), initial application (vitakka), sustained application (vicāra), rapture (pīti), one-pointedness of mind (cittass'ekaggatā), the life faculty (jīvitindriya); or whatever other dependently arisen, immaterial phenomena (dhammā) there are on that occasion — excepting the aggregate of feeling (vedanākkhandha), excepting the aggregate of perception (saññākkhandha), excepting the aggregate of consciousness (viññāṇakkhandha) — this on that occasion is the aggregate of volitional formations. … These phenomena are indeterminate (abyākata). The wholesome-resultant mind-consciousness element (manoviññāṇadhātu) accompanied by joy (somanassa).

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 5 other places