妙法蓮華經玄義 4.76

4.76

此二十五皆稱三昧者，調直定也。真諦以空無漏為調直；出假以稱機為調直；中道遮二邊為調直。故皆具三諦，則通稱三昧。又稱王者，空、假調直，未得為王，所以二乘入空，菩薩出假，不名法王。中道調直，故得稱王。一一三昧皆有中道，悉稱為王。《大經》云：「是二十五三昧名諸三昧王」，即其位高義；「若入是三昧，一切三昧悉入其中」，即其體廣義；「應二十五有機」，即其用長也。

The reason why these twenty-five are all called samādhi is that [samādhi means] attuned and upright concentration. The true truth takes emptiness and the outflow-free as attuned and upright; emerging into the provisional takes matching spiritual capacities as attuned and upright; the Middle Way takes warding off the two extremes as attuned and upright. Thus, all possessing the three truths, they are universally called samādhi. Furthermore, the reason why they are called king is that being attuned and upright in emptiness and the provisional does not yet allow one to be a king; this is why the two vehicles entering emptiness and the bodhisattva emerging into the provisional are not called Dharma kings. Being attuned and upright in the Middle Way allows one to be called a king. Each and every samādhi possesses the Middle Way, and all are called kings. The Great Sūtra says: 'These twenty-five samādhis are called kings of all samādhis,' which is the meaning of their sublime position; 'If one enters this samādhi, all samādhis enter into it,' which is the meaning of the vastness of their substance; 'Responding to the capacities of the twenty-five realms of existence,' which is the meaning of the enduring nature of their function.