妙法蓮華經玄義 4.151

4.151

七、不時解脫羅漢者，即是法行利根，名不動法阿羅漢也。此人因中修道，能一切時，隨所欲進修善業，不待眾具，故名不時解脫。是人不為煩惱所動，故名不動。不動是不退義。成就三智：謂盡智、無生智、無學等見。能用重空三昧，擊聖善法，以定捨定，故言能擊。

Seventh, the arhat liberated at all times: this is one of sharp faculties who practices according to Dharma, called an arhat of immovable dharma. When cultivating the path in the causal stage, this person can advance and cultivate good karma at all times as they wish, without awaiting various provisions; hence called liberated at all times. This person is not moved by afflictions, hence called immovable. Immovable means not falling back. They accomplish the three knowledges: namely, the knowledge of exhaustion, the knowledge of non-arising, and the view of the non-learner and so forth. They can use the double-emptiness samādhi to strike noble wholesome dharmas, relinquishing concentration by means of concentration; hence it is said that they can strike.