[507] Therein, what is zeal (chanda)?
That which is zeal, zealousness, the desire to act, wholesome zeal for dhammas — this is called zeal.
Therein, what is concentration (samādhi)?
That which is stability of the mind (citta), steadiness, steadfastness, non-wavering, non-scatteredness, the state of an unwavering mind, calm (samatha), the faculty of concentration, the power of concentration, right concentration — this is called concentration.
Therein, what is the volitional formation of striving (padhānasaṅkhāra)?
That which is the mental arousal of energy (viriya), exertion, striving, endeavor, effort, vigor, perseverance, stamina, fortitude, the state of unslackened striving, the state of not relinquishing zeal, the state of not relinquishing the task, firmly upholding the task, energy, the faculty of energy, the power of energy, right effort — this is called the volitional formation of striving.
Thus, one is furnished, fully furnished, provided, fully provided, possessed, fully possessed, and endowed with this zeal, with this concentration, and with this volitional formation of striving; therefore it is said: "endowed with zeal, concentration, and the volitional formation of striving" (chandasamādhipadhānasaṅkhārasamannāgato).
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.