成唯識論述記 6.154

6.154

述曰：謂於四境更互除一。謂初於所樂、決定、曾習、所觀起初四除惠，如是於前四境除定取惠。如是於前四境中除曾習，即於三境起四，除念取定。如是四境中除決定，於三境中起四，除解取念。如是四境除所樂，於三境起四，除欲取勝解，即互除一。合四境起亦有五个四也。此中但舉後一、初一，一一料簡，如前可知。

The Commentary states: That is, mutually omitting one across the four objects. That is, first, toward the agreeable, the determined, the previously practiced, and the contemplated, the first four arise, omitting wisdom; in this way, toward the preceding four objects, concentration is omitted and wisdom is taken. In this way, among the preceding four objects, the previously practiced is omitted, so that four arise toward three objects, omitting mindfulness and taking concentration. In this way, among the four objects, the determined is omitted, so that four arise toward three objects, omitting resolve and taking mindfulness. In this way, the four objects omit the agreeable, so that four arise toward three objects, omitting desire and taking resolve; thus each mutually omits one. Combined across the four objects, there are also five sets of four arising. Here it merely adduces the last one and the first one; analyzing them one by one, it can be known as above.