金剛經纂要刊定記 4.102

4.102

不可思量者，以是無相施福故不可思量，喻中東方是眾方之首，是故先明，南西北方如次例說，法喻皆同不可思量，意云：非謂無空，此空相對，義在合中。

Regarding "incalculable": because it is the merit of markless giving, it is incalculable. In the metaphor, the east is the foremost of all directions, so it is clarified first; south, west, and north are exemplified in order. Both the dharma and the metaphor are equally incalculable. The intention is: it does not mean there is no space; this relative space holds its meaning within the application of the metaphor.