法界次第初門 2.187

2.187

二、正思惟。見四諦時，無漏心相應，思惟動發，覺知籌量，為令增長，入涅槃故，名正思惟。

Second, right thought. When seeing the four noble truths, corresponding with the untainted mind, thinking stirs and arises, recognizing and weighing in order to bring about increase and enter nirvāṇa; hence it is called right thought.