It’s like when the heavens rain heavily on a mountain top, and the water flows downhill to fill the hollows, crevices, and creeks. As they become full, they fill up the pools. The pools fill up the lakes, the lakes fill up the streams, and the streams fill up the rivers. And as the rivers become full, they fill up the ocean. That’s the fuel for the ocean, and that’s how it’s filled up.

In the same way, when the factor of associating with true persons is fulfilled, it fulfills the factor of listening to the true teaching. When the factor of listening to the true teaching is fulfilled, it fulfills the factor of faith … rational application of mind … mindfulness & situational awareness … sense restraint …the 3 kinds of good conduct … the 4 kinds of mindfulness meditation … the 7 awakening factors. When the 7 awakening factors are fulfilled, they fulfill knowledge and freedom. That’s the fuel for knowledge & freedom, and that’s how it’s fulfilled.”

Partial excerpts from AN 10.61 : Avijjasutta