瑜伽論記 17.508

17.508

第三、解靜慮四種異名。何故名三摩地乃至任持心故者，泰云：梵音三摩地，此云等持。於本識所現事前後相似名同分為同分，為定心本境所緣所知，定心相分有一切影像境起，緣此境時離沈浮住平等持。心住一境，名等持。

Third, explaining the four different names of dhyāna. Regarding why it is named samādhi up to sustaining the mind: Tai says: The Sanskrit word is samādhi; here translated as 'equal holding' (dengchi). The events appearing in the fundamental consciousness being similar before and after is called 'sharing the same category' (sabhāga); as the fundamental sphere, intentional object, and knowable of the concentrated mind, all perceptual images of spheres arise in the image-part of the concentrated mind; when taking this sphere as intentional object, one remains in equal holding free from sinking and floating. The mind abiding on a single intentional object is called 'equal holding'.