首楞嚴義疏注經 8.456

8.456

謂由不斷三業，各各有私，故云別造。因各各私，眾私同分，故云入同分地，謂同業共感無差別同分，別業各感差別同分，故前文云「眾同分中兼有元地」也。皆由妄想發起，故非本有。

This means that because they do not sever the three karmas, each has personal [karmas], hence it says "create separately." Because of their individual personal [karmas], the many personal [karmas] share a common destiny; hence it says "enter realms of common destiny." This means that shared karma collectively brings on undifferentiated common destiny, while separate karma individually brings on differentiated common destiny; therefore the earlier text stated, "Within the common destiny there is also a primordial ground." All are brought forth by false imagination, so they are not fundamentally existent.