釋氏要覽 3.332

3.332

北俗亡。累七。齋日。皆令主齋僧。剪帋幡子一首。隨帋化之。按正法念處經。有一十七種中有。謂死時。若生天者。即見中有如白㲲垂下。其人識神見已。舉手攬之。便受天人中有身。故今七七日。是中有死生之日。以白紙幡子勝幢之。相示之故此人招魂帛。皆用白練。甚合經旨也。

According to northern custom, on the cumulative-seven fasting days after a death, they always have the presiding monk cut out a paper banner and burn it along with paper. According to the Saddharmasmṛtyupasthāna-sūtra, there are seventeen kinds of intermediate states. It says that at the time of death, if one is to be born in heaven, one sees the intermediate state hanging down like white fine cotton cloth; when the person's conscious spirit sees it, he raises his hand to grasp it, and immediately receives the intermediate state body of a god or human. Therefore, now the forty-ninth day (seven sevens) is the day of death and birth of the intermediate state; using a white paper banner manifests the sign of a victory banner. For this reason, the soul-summoning silk for such a person always uses plain white silk, which accords very well with the meaning of the sūtras.