首楞嚴義疏注經 3.442

3.442

前三句顯虛空之大義也。虛空若從因緣所生，體非周遍，復是動搖，豈名為大？夫言大者常遍為義，常故無生滅動搖，遍故時處悉有。若因緣生，此有彼無、現有未無，緣會則生、緣離則滅。今此不爾，本如來藏，本自周遍，本不動搖，故名為大。當知下六句，類前四性同受大名。咸稱大者，皆周遍故、無動搖故、是藏性中真功德故、無方大用遍一切處作利益故，豈同方便有名無實而稱大耶？

The first three lines reveal the meaning of 'great' for empty space. If empty space arose from causes and conditions, its substance would not be all-pervading and would also be moving; how could it be called 'great'? That which is called 'great' has the meaning of permanence and ubiquity: being permanent, it has no arising, ceasing, or motion; being ubiquitous, it exists in all times and places. If it arose from causes and conditions, it would exist here and not there, exist now and not in the future; assembling conditions it would arise, and separating conditions it would cease. Now this is not so: fundamentally it is the tathāgatagarbha, fundamentally all-pervading, fundamentally unmoving; hence it is called 'great'. The six lines from 'You should know...' assimilate the previous four natures to equally receive the name 'great'. They are all called 'great' because they are all-pervading, unmoving, the true virtues within the womb-nature, and their unbounded great function pervades everywhere to benefit beings. How could this be like the expedient teachings, having only the name without the reality, yet being called 'great'?