仁王經疏 2.243

2.243

釋曰：第三、約時讚德。謂一切眾生，雖無有始而有盡時，名暫住報。唯佛一人，有始無終，名居淨土。

The commentary states: Third, praising virtue in terms of time. This means that although all sentient beings have no beginning, they have a time of termination; this is called 'temporarily dwelling in retribution.' The Buddha alone has a beginning and no end; this is called 'dwelling in the pure land.'