妙法蓮華經玄贊 6.80

6.80

贊曰：陳車在外也。果出於因門、理逾於教外，故言出門外。車體無漏不繫名外。若離三界無施化處故，在三乘門外也。佛住宅外，故呼子出。義如前釋。

Commentary: This sets forth that the carts are outside. The fruit emerges from the gate of causes, and the principle surpasses what lies outside the teaching; therefore it is said they are "outside the gate." The substance of the cart is untainted (anāsrava) and unconditioned, which is called "outside." If it were separated from the triple realm, there would be nowhere to enact conversion; hence they are "outside the gates of the three vehicles." The Buddha dwells outside the house, so he calls for his children to come out. The meaning is as explained before.