法華義疏 3.266

3.266

若佛知住起謗故不為說者，《釋論》明喜根、勝意二人，勝意執小、喜根悟大，遂為勝意說大乘，而勝意便誹謗墮大地獄，未來因此畢苦果而得解脫。今何不為說耶？

If the Buddha did not preach for them because he knew that staying would cause them to slander, the Śāstra (Da zhidu lun) explains the two figures Xigen and Shengyi: Shengyi clung to the Hīnayāna while Xigen awakened to the Mahāyāna, whereupon [Xigen] preached the Mahāyāna to Shengyi, and Shengyi slandered it and fell into the great hells, but in the future, through this, he exhausted the painful retribution and attained liberation. Why does [the Buddha] not preach to them now?