Quotes from Jin gang bo re jing shu lun zuan yao, Vol. 1
"When the Buddha was to enter nirvana, Ananda asked Him four questions, each of which the Buddha answered. The Buddha said, “After I enter nirvana, all my disciples should first abide by the Four Foundations of Mindfulness. Second, they should observe the precepts as their teacher. Third, they should composedly alienate themselves from evil-natured bhikkus. Fourth, the opening lines of all sutras should be ‘At one time, thus have I heard,’ and it should be stated where the Buddha was and with whom, how many were in attendance, and so forth.”
《金剛般若經疏論纂要》卷一
「則佛臨滅度，阿難請問四事，佛一一答。我滅度後，一依四念處住
；二以戒為師；三默擯惡性比丘；四一切經初，皆云如是我聞一時佛
在某處與某眾若干等。」