《明史·志·卷五十》
年终，移交钦天监，选择吉日和香料入水，在皇极门洗涤宝玺。
岁终，移钦天监，择日和香物入水，洗宝于皇极门。
At the end of the year, transfer the seals to the Imperial Astronomical Bureau, choose a good day and spices to wash the seals in the imperial gate.