起信論疏筆削記 15.40

15.40

又優婆塞眾中，有十六人，昔曾於閻浮提皆作國王，隨順惡友非法說法，墮阿鼻獄。由曾聞法，今得遇佛而見世尊，如黑象脚。佛令懺悔，並見金色，成阿羅漢。

Furthermore, among the assembly of upāsakas, there were sixteen people who had previously been kings in Jambudvīpa; following bad companions, they preached what was not Dharma as Dharma, and fell into Avīci Hell. Due to having once heard the Dharma, they now were able to meet the Buddha and see the World-Honoured One like a black elephant's foot. The Buddha instructed them to repent, and all of them saw his golden color and became arhats.