無量壽經優婆提舍願生偈註 1.34

1.34

此二句名莊嚴光明功德成就。佛本何故興此莊嚴？見有國土，雖復項背日光，而為愚癡所闇。是故願言：使我國土所有光明，能除癡闇入佛智慧，不為無記之事。亦云：安樂國土光明，從如來智慧報起，故能除世闇冥。經言「或有佛土以光明為佛事」，即是此也。故言佛慧明淨日，除世癡闇冥。

These two lines are called the accomplishment of the adornment of light merits. Why did the Buddha originally give rise to this adornment? He saw that there are lands where, although beings have the sunlight at their necks and backs, they are darkened by ignorance. For this reason he made this vow: 'May all the radiance in my land be able to dispel the darkness of ignorance and enter the Buddha's wisdom, and not serve neutral, worldly matters.' It is also said: The radiance of the Land of Peace and Bliss arises from the recompense of the Tathāgata's wisdom, and therefore can dispel the darkness of the world. The sūtra says: 'There are Buddha lands that take light to perform Buddha deeds.' This is precisely it. Therefore it is said: 'The bright, pure sun of the Buddha's wisdom / Dispels the dark ignorance of the world.'