瑜伽論記 7.261

7.261

基云：四神足體是定，從因為名說欲等也，又定為神通之足，故名神通足，又定名神，此四是神之足心，神足則生心王也。棧法師云：又或是定。

Ji says: The substance of the four bases of psychic power is meditative absorption (samādhi); desire and so forth are named after their causes. Furthermore, meditative absorption serves as the foot of psychic power; hence it is called “foot of psychic power.” Furthermore, meditative absorption is named “spirit/psychic,” and these four are the mental feet of this spirit, so the psychic feet give rise to the king of the mind. Master Zhan says: Or again, it is meditative absorption.