仁王護國般若波羅蜜多經疏 2.379

2.379

解曰：重言如是者，如汝所說印能詮文得真實義者印所詮義，是故重言如是如是。不可思議者讚其文義心言路絕。從此第四唯佛能知。

The commentary explains: Repeating 'so it is': 'just as you have said' confirms the expressive text; 'attained the real meaning' confirms the expressed meaning. Therefore, it is repeated: 'so it is, so it is.' 'Inconceivable' praises the fact that its text and meaning cut off the path of thought and words. From here, the fourth part shows that only buddhas can know this.