“Bhikkhus, just as whatever kinds of seed and plant life attain to growth, increase, and expansion, all do so based upon the earth, established upon the earth, so too, based upon virtue, established upon virtue, a bhikkhu develops and cultivates the Noble Eightfold Path, and thereby he attains to growth, increase, and expansion in wholesome states.
“And how does a bhikkhu do so? Here, bhikkhus, a bhikkhu develops right view … right intention … right speech … right action … right livelihood … right effort … right mindfulness … right concentration, which is based upon seclusion, dispassion, and cessation, maturing in release. It is in this way, bhikkhus, that a bhikkhu, based upon virtue, established upon virtue, develops and cultivates the Noble Eightfold Path, and thereby attains to growth, increase, and expansion in wholesome states.”
Read this translation of Saṁyutta Nikāya 45.150 Bījasutta: Seeds by Bhikkhu Bodhi on SuttaCentral.net.