Interpretation:

God is telling us that when we get an illness, this may be a guidance from God to sweep your mind of dust. These dusts in the mind are regret, covetousness, greed, arrogance and self-love. These are the dust we are all prone to act on.

Definitions:

Minouchi: within the body

Nayamu: suffering

Koto: matter

Oba: God, grandmother

Shiyan: ponder

Shite: to do

Kami: God

Motareru: to accept

Kokoro: mind

Shiyan: to ponder