I've heard a few pieces of advice the Buddha gave to arahants, but not much. What are some teachings the Buddha gave to arahants to guide them towards further growth?
I want to clarify a bit what I mean for I feel I didn't do an adequate job of explaining my question.
After enlightenment, there is nothing more to be done, but a phenomena seems to occur. The self is known to be illusory. The bodymind (the forms within experience that was previously identified with) continue to appear and slowly seems to embody the enlightened perspective.
This is outlined in this quote from this answer which was posted here on this forum in the past.
A Hinayana arhat abandoned afflictive obscurations by way of realizing emptiness, but has not abandoned knowledge obscuration. He has achieved abiding nirvana. Therefore, although they are free from the conception of true existence, and from true suffering, they are not free from the imprints of ignorance (i.e. knowledge obscurations). We say that it is like removing garlic from a container: the smell will still be there. So, because they still have the imprints of ignorance, (1) they are not free from the appearance of true existence, and (2) they are reborn with a mental body, due to the imprints of ignorance (in our case, we are reborn to due karma and afflictions).
A bodhisattva is a person who generated effortless bodhicitta (the wish to achieve enlightenment for the sake of all sentient beings). Since effortless bodhicitta is the entry gate to the Mahayana path, he entered the Mahayana small path of accumulation. When he cultivates wisdom, it is conjoined with emptiness and that makes his mind vast (due to bodhicitta) and profound (due to realizing emptiness). He wishes not to abide in individual liberation (abiding nirvana) but to be free from the extreme of peace (abiding nirvana) as well as from samsara. Therefore, he wishes to achieve non-abiding nirvana, which is the attainment of a buddha.
A Buddha abandoned both afflictive and knowledge obscuration, having generated the path perfection of wisdom (the wisdom of emptiness conjoined with bodhicitta). In his continuum, wisdom and bodhicitta are the same mind: the omniscient mind of a buddha that realizes all objects of knowledge directly, past present and future, in an unmistaken way, etc. He achieved non-abiding nirvana, abiding neither in samsara nor in individual liberation. His enlightened activities are uninterrupted.
This is apparently a quote from a zen master that illustrates the same thing.
A zen monk was once asked, “How’s your enlightenment going?” And he replied, “Fine. My body is having a hard time keeping up with it though.”
I am hoping to find content of this nature that describes how this process of going from an arahant to a Buddha unfolds.