摩訶止觀 8.120

8.120

若人自念：此病困苦，皆由往日不善折致，深生慚愧，不敢為非；雖嬰困篤，而善心無改，起上、中、下善。是為因病造三善法界。

If a person reflects to themselves: "The distress and suffering of this illness are all brought about by past unwholesomeness," deeply generating shame and remorse, and dare not do evil; even though beset by severe distress, their wholesome mind does not alter, giving rise to upper, middle, and lower goodness. This is creating the three wholesome dharmadhātus due to illness.