法華玄贊義決 1.304

1.304

正為聲聞不定性者，故論云示現種子無上故說雨譬喻，汝等所行是菩薩道者，謂發菩提心退已還發，前所修行善根不滅，同彼後得果故。意說二乘身中有菩薩種子，但能還修皆得作佛，已發心者令堅固故，未發心者令聞無上亦發心故。既云退已還發心，前所修行善根不滅，同後得果故，明為不定。

They are specifically for śrāvakas of indeterminate lineage. Therefore the treatise states: "To demonstrate the unsurpassable seed, the rain parable is spoken." "That which you practice is the bodhisattva path" means that having generated the mind of awakening, falling back and then generating it again, the roots of good previously practiced are not destroyed, because they are identical to that fruit obtained later. The meaning is that within the bodies of the two vehicles there is the bodhisattva seed; as long as they can practice again, all will attain buddhahood. It is to cause those who have already generated the mind to become firm, and to cause those who have not yet generated the mind to also generate the mind upon hearing the unsurpassable. Since it is said that falling back and then generating the mind again, the roots of good previously practiced are not destroyed because they are identical to the fruit obtained later, it clearly pertains to the indeterminate [lineage].