AN 3.68 excerpt, illustration of important learning feature in oral tradition

The part I highlighted in yellow, that's the important two words to memorize, that un-wise-attention is the nutriment for delusion.

The 3 repetitions highlighted in green, is a common phrase that occurs often in the suttas, such as SN 46.2.

Now here's the magic part. 

If you recite it regularly everyday, as slow as necessary as to be able to  reflect on the meaning, it has the effect of giving you a positive brain wash. Training your mind to do the right things, and eventually making it into a habit. Once you train yourself to think "yoniso mansikaro" all the time.

memorizing the necessary parts: 

The rest of this sutta AN 3.68, is redundant with the content of  an important sutta you should already have memorized, SN 46.2 (substitute raga for kama-chanda and doso for byapada hindrances), so all you need to memorize is the excerpt in this post.

( delusion worst of the 3 a.m. )

‘rāgo kho, āvuso, appa-sāvajjo dandha-virāgī,	‘Greed, reverends, is mildly blameworthy, but slow to fade away.
doso mahā-sāvajjo khippa-virāgī,	Hate is very blameworthy, but quick to fade away.
moho mahā-sāvajjo dandha-virāgī’ti.	Delusion is very blameworthy, and slow to fade away.’

...

( moho ← A-yoniso manasi-kāro )

‘Ko panāvuso,	And if they ask:
hetu ko paccayo yena	‘What is the cause, what is the reason why
an-uppanno vā moho uppajjati	un-arisen delusion arises, (and)
uppanno vā moho bhiyyo-bhāvāya vepullāya	arisen delusion increases (and) grows.
saṃvattatī’ti?	(why does that) lead-to-this (result)?
‘“A-yoniso manasi-kāro”tissa vacanīyaṃ.	You should say: ‘un-wise attention.
Tassa a-yoniso manasi karoto	with un-wise attention
an-uppanno vā moho uppajjati	un-arisen delusion arises, (and)
uppanno vā moho bhiyyo-bhāvāya vepullāya	arisen delusion increases (and) grows.
saṃvattati.	(that) leads-to-this (result).
Ayaṃ kho, āvuso, hetu	This is the cause,
ayaṃ paccayo yena	this is the reason why
an-uppanno vā moho uppajjati	un-arisen delusion arises, (and)
uppanno vā moho bhiyyo-bhāvāya vepullāya	arisen delusion increases (and) grows.
saṃvattatī’ti.	(this is why that) lead-to-this (result).