法華義疏 6.167

6.167

所言立者，將行之貌也。以將入宅救子，所以言立。又言立者，不行之像，譬佛待機方入生死度物而不他行也。又言立者，諸子背化流轉生死，如來眾德久已成立。又言立者不安之貌，聖人雖復息跡世外，恒欲府入生死未曾暫安也。

Speaking of "standing," it is the appearance of being about to go. Because he is about to enter the house to rescue the children, it therefore says "standing." Furthermore, "standing" is the image of not walking, a parable for the Buddha awaiting the capacity before entering birth and death to cross over beings, without going elsewhere. Furthermore, "standing" means that while the children turn their backs on the teaching and wander through birth and death, the Tathāgata's manifold virtues have long been established. Furthermore, "standing" is an appearance of being unsettled; although the sage has withdrawn his traces beyond the world, he constantly desires to lean down and enter birth and death, never being settled even for a moment.