觀無量壽佛經疏 2.107

2.107

六、從時韋提白佛下，至見彼國土已來，明其夫人重牒前恩，欲生起後問之意。此明夫人領解佛意，如上光臺所見，謂是己能。向見世尊開示，始知是佛方便之恩。若爾者，佛今在世，眾生蒙念，可使得見西方。佛若涅槃，不蒙加備者，云何得見也。

Sixth, from 'Then Vaidehī said to the Buddha' down to 'seeing that land' clarifies that the Queen reiterated the previous grace, wishing to introduce the subsequent question. This clarifies that the Queen understood the Buddha's intent: as for what was seen on the platform of light above, she had thought it was her own ability. Having just seen the World-Honoured One's revelation, she only then knew that it was the grace of the Buddha's expedient means. If so, while the Buddha is currently in the world, sentient beings, receiving his mindful care, can be enabled to see the West; but if the Buddha enters nirvāṇa and they do not receive his assistance, how can they see it?