In Ven. P. A. Payutto’s essay on Sammasati (Trans. by Ajahn Jayasaro), it includes the following verse on appamada, but I believe the citation is incorrect and I’m hoping someone might be able to provide the correct one so I could locate it in the Bhikkhu Bodhi AN.
"Is there any single dhamma which provides both sorts of benefit, both present and immediate benefit and future or higher benefit?
Yes there is.
What is that Dhamma?
That Dhamma is heedfulness. (Listed as being A.III.364, but mistaken I believe)
And here is another from the same essay that I also can’t locate … but perhaps I’m not understanding the citation system being used and if so, I apologize:
“Just as the light of dawn precedes the sunrise and is its harbinger; so
the perfection of heedfulness leads to and is the harbinger of the Noble
Eightfold Path … The single dhamma which is of most assistance in
the arising of the Noble Eightfold Path is the perfection of heedfulness … I
see no other kind of dhamma which has such power to cause the as-yet
unarisen Noble Eightfold Path to arise, and the Noble Eightfold Path which has
arisen to come to maturity and completion. A bhikkhu who is heedful may expect to develop and cultivate the Noble Eightfold Path.” [S.V.31, 32, 33, 35, 36, 37, 41-45]