楞伽阿跋多羅寶經註解 2.21

2.21

The previous contemplation was on the inner mind; this cultivates the external contemplation. The cultivation of these two contemplations accords with what is appropriate, and they need not necessarily both be employed. 'Contemplating external existents as non-existent' means understanding that the nature of external dharmas is not produced from the four natures—self, other, and so forth; that is, their nature is like a mirage, a dream, an illusion, and so forth. Because all these dharmas have beginningless false vāsanā as their cause, they are all unreal like mirages and dreams; this is skillfully contemplating external existents as non-existent.