金光明最勝王經疏 2.36

2.36

經　於蓮華上｀有四如來，東方不動、南方寶相、西無量壽、北天鼓音。是四如來，各於其座加趺＇而坐。

Sūtra: Upon the lotus flowers were four Tathāgatas: Akṣobhya in the east, Ratnaketu in the south, Amitāyus in the west, and Dundubhisvararāja in the north. These four Tathāgatas were each seated cross-legged on their thrones.