妙法蓮華經玄贊 9.481

9.481

贊曰：三觀機道隱喻。眾生根機時猶未熟、他方機會，化身遂隱往他方化，或往淨土、穢土行化，名為餘國。

The Commentary says: The third is the parable of observing capacities and concealing the Way. Because the faculties and capacities of sentient beings were not yet mature, while the occasion was ripe elsewhere, the transformation body concealed itself and went elsewhere to convert [beings]. Or, proceeding to pure lands or defiled lands to carry out conversion is called "another land."