仁王經疏 1.129

1.129

言得九十忍者，第九德。上來已釋小乘觀門，今向大乘便成九十。謂初入十信，皆有九品，故言九十忍。又解：學十解已上三十心，皆有入、住、出三位，故成九十忍。又解：極喜等十地，各有始、住、終三，三中一一各有三品，故言九十。一云：四三二一總攝為二，初四三二合說為九，更加一數即成十數。故言九十（淨公說）。一云：四三二一總計為十，皆有九品，故言九十。一云：諦觀二十，謂十六諦及四諦。品觀有十，謂四三二一。總計合成三十，皆有三品，故言九十。

The phrase "attaining the ninety patiences" is the ninth virtue. Having already explained the Hīnayāna contemplation approaches above, turning now to the Mahāyāna, they become ninety. That is, upon initial entry into the ten faiths, each has nine grades; therefore it says ninety patiences. Another explanation states: From the study of the ten understandings upwards through the thirty minds, each has three stages of entering, abiding, and emerging; hence they constitute ninety patiences. Another explanation states: The ten grounds, such as Pramuditā, each have three—beginning, abiding, and final; within the three, each has three grades; therefore it says ninety. One says: Four, three, two, and one are subsumed into two; the initial four, three, and two together make nine, and adding one more number makes the number ten; therefore it says ninety (this is the explanation of Master Jing). One says: Four, three, two, and one are counted together as ten, each having nine grades; therefore it says ninety. One says: The truth contemplations are twenty, namely the sixteen truths and the four truths; the stage contemplations are ten, namely four, three, two, and one; counted together they make thirty, and each has three grades; therefore it says ninety.