Question: How do you know this?
Answer: Regarding what sutra were preached after the Flower Garland Sutra, the "Introductory" chapter of the Lotus Sutra states, "To those who suffer, hating old age, sickness and death, the Buddha preaches the teaching of Nirvana, showing ignorant people the way to tranquility and extinction of worldly passions." In the "Expedients" chapter of the Lotus Sutra, it states, "The Buddha went to the Deer Park in Baranasi Kingdom.... and preached the dharma to five monks." It is also stated in the Nirvana Sutra, "The Buddha preached on the Middle Way in the Deer Park of the Baranasi Kingdom." This indicates what sutras were preached after the Flower Garland Sutra. According to these scriptural statements, it seem clear that it was the Agama sutras for sravaka disciple which were expounded after the Flower Garland Sutra for great bodhisattvas.