This was said by the Blessed One, said by the Arahant, as I have heard:

"Bhikkhus, a bhikkhu who is lacking continuous effort and is without concern is incapable of full awakening, incapable of Nibbāna, incapable of attaining the unsurpassed safety from bondage. But, bhikkhus, a bhikkhu who is endowed with continuous effort and endowed with a sense of shame is capable of full awakening, capable of Nibbāna, capable of attaining the unsurpassed safety from bondage.

The Blessed One spoke on this matter. In this regard, it is said:

"Lacking continuous effort and without concern, a lazy person who is weak in effort; Overcome by dullness and drowsiness, without shame, and without respect; Such a bhikkhu is incapable, of reaching the highest awakening.

But one who is mindful, discerning and meditates, with continuous effort, with concern, and diligent; Having cut off the fetter of birth and old age, such a one, in the here and now, reaches the highest awakening."

This matter too was spoken by the Blessed One, as I have heard.