妙法蓮華經玄贊 9.479

9.479

贊曰：二慈矜起化喻。有二乘種方稱為子，故言十二十，兼菩薩性，為不定故。言至百數，脩百行故，初教發心位也。

The Commentary says: The second is the parable of arousing transformation through loving compassion. Only those endowed with the lineage of the two vehicles are properly called "sons"; hence [the sūtra] says "ten, twenty." As they are also conjoined with the bodhisattva nature, they are indeterminate. When it says "even up to a hundred," this is because they practice a hundred practices; this refers to the stage of being initially taught to arouse the mind [for awakening].