The Tipiṭaka in Three Languages

Suññatavāra

Abhidhammapiṭaka · Dhammasaṅgaṇī · Vol. 34 · Section 287

[287] What on that occasion is the faculty of concentration (samādhindriya)? That which on that occasion is stability of mind (citta), steadfastness, steadiness, non-wavering, non-distraction, the state of an unwavering mind, calm (samatha), the faculty of concentration, the power of concentration, wrong concentration (micchāsamādhi) — this on that occasion is the faculty of concentration.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 5 other places