
The Blessed Buddha once
said:
What, Bhikkhus, is the
Ability
to
Understand?
Here, Bhikkhus, any Noble Disciple, who is both intelligent and wise;
is endowed with understanding of cause and effect,
is endowed with understanding of arising and ceasing,
is endowed with understanding of conditioned dependency,
which is Noble, penetrative,
and leading to the complete irreversible
elimination of any and all Suffering...
He understands it, as it really is: This is Suffering!
He
understands it, as it really is: Craving is the Cause of Suffering!
He understands it, as it really is: No craving is the Ceasing of Suffering!
He understands it, as it really is:
The Noble 8-fold Way is the End of Suffering!
This is called the
Ability
to
Understand!
Understanding is knowing,
and seeing the 4 Noble Truths!
Ignorance is not knowing, and not seeing the 4 Noble Truths!

More on this ability to
understand (PaññA Indriya):
https://What-Buddha-Said.net/drops/Freed_by_Knowing.htm
https://What-Buddha-Said.net/drops/IV/The_Chief_Ability.htm
https://What-Buddha-Said.net/library/DPPN/wtb/n_r/pannaa.htm
https://What-Buddha-Said.net/drops/III/Right_Understanding.htm
https://What-Buddha-Said.net/drops/Understanding_is_the_Chief.htm
https://What-Buddha-Said.net/drops/III/Supreme_Understanding.htm
https://What-Buddha-Said.net/drops/III/Revealing_Understanding.htm
https://What-Buddha-Said.net/drops/III/The_Understanding_Ability.htm
https://What-Buddha-Said.net/drops/III/Outstanding_Understanding.htm

Source (edited extract):
The Grouped Sayings of the Buddha.
Samyutta Nikāya.
Book [V:199]
section 48: The Abilities. 10: Analysis ...