How to Feed the ability to Investigate all states!

The Blessed Buddha once said:
Bhikkhus, as this body, is sustained by feeding, exists in dependence on
feeding & cannot survive without food, so are the 7 Links to Awakening
also sustained by feeding, they can only exist in dependence on feeding
and they cannot survive without feeding... And what is the feeding of the
emergence of any yet unarisen Investigation & feeding of the completion
by progress of already arisen Investigation of states Link to Awakening?

This formula: There are states that are:
1: Advantageous or Disadvantageous.
2: Blamable or Blameless.
3: Ordinary or Excellent.
4: On the Bright side or on the Dark side.

Frequently giving careful & rational attention to them, is feeding arising
of any unarisen ability to investigate & feeding also for the fulfillment
of any already arisen Investigation of states Link to Awakening...

And what, Bhikkhus, is the starving that obstructs the emergence of yet
unarisen ability to investigate & which also hinders ongoing Investigation?
There are, bhikkhus, things that are advantageous or disadvantageous,
blamable or blameless, ordinary or excellent and on the bright side or on
the dark side: not giving frequent, careful & rational attention to them,
not considering them much and often, is the starving  that prevents any
unarisen ability to investigate from arising and also blocks any already
arisen investigation of states link to awakening from reaching complete
fulfillment and refinement by mental development...

Comments from the classical commentaries:
Examining is the characteristic of the Investigation Link to Awakening
(Dhamma-Vicaya-sambojjhanga). Scrutiny, inspection, inquiry, exploration,
analysis, research & repeated review is the purpose of the investigation.
Interested and eager curiosity is the manifestation of this investigating.
Before, while and after doing any mental, verbal or bodily action simply
then ask yourself: Is this behaviour advantageous or disadvantageous,
blamable or blameless, ordinary or excellent, on the bright or dark side
and act accordingly! Keep on refining this crucial ethical discrimination!

Conditions helpful for the emergence of the ability to investigate are:
1: Asking questions to yourself and those you respect.
2: Clean, healthy and hygienic mental, physical and bodily praxis.
3: Avoidance of people with reduced and confused understanding.
4: Friendship with people with exact and profound understanding.
5: Repeated reviewing reflection on all the deeper questions.
6: Commitment to finding out precisely why and how: Cause and effect!

There is investigation of external states and there is investigation of
internal states. Both are crucial for all progress towards understanding.
Awakening is a pure knowing that is the result of perfect investigation!

Sources (edited extracts):
The Grouped Sayings of the Buddha. Samyutta Nikāya.
Book [V: 65-6+102-8] 46: Links. 2+51: Group & Nutriments....

Feeding the ability to Investigate!