維摩經玄疏 5.79

5.79

答曰：須彌入芥，小不障大，大不礙小，故云不思議耳。今有煩惱結惑，不障智慧涅槃；智慧涅槃，不礙煩惱結惑，乃名不思議。其無惑有智而入涅槃稱不思議者，今即反難：亦應「無芥子之小，有須彌之大」論不思議耶！

Answer: Mount Sumeru enters a mustard seed; the small does not obstruct the large, and the large does not hinder the small; hence it is called inconceivable. Now, having afflictions, fetters, and delusions does not obstruct wisdom and nirvāṇa; wisdom and nirvāṇa do not hinder afflictions, fetters, and delusions—only this is called inconceivable. If entering nirvāṇa with no delusion and having wisdom were called inconceivable, we would now raise a counter-objection: should not 'having no smallness of a mustard seed, but having the largeness of Mount Sumeru' also be treated as inconceivable?!