Aggisutta

Suttapiṭaka · Saṁyuttanikāya · Mahāvaggasaṁyutta · Vol. 19 · Section 569

[569] "Bhikkhus, when the mind (citta) is sluggish, that is not the time to develop the tranquility factor of awakening (passaddhisambojjhaṅga); it is not the time to develop the concentration (samādhi) factor of awakening; it is not the time to develop the equanimity factor of awakening. For what reason? Because a sluggish mind, bhikkhus, is difficult to arouse by those dhammas. Suppose, bhikkhus, a man wishing to make a small fire blaze up were to throw wet grass upon it, were to throw wet cow dung upon it, were to throw wet timber upon it, were to give it a water-laden wind, and were to scatter dust upon it — would that man be able to make that small fire blaze up?" "Surely not, venerable sir." "So too, bhikkhus, when the mind is sluggish, that is not the time to develop the tranquility factor of awakening; it is not the time to develop the concentration factor of awakening; it is not the time to develop the equanimity factor of awakening. For what reason? Because a sluggish mind, bhikkhus, is difficult to arouse by those dhammas."

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.