摩訶止觀 9.44

9.44

心作喜、心作攝者：前喜從三十六物生，此直就心作喜，故知對二禪。《大集》明二禪但三支，無內淨。今心作喜，意似於此。作攝者：喜動則散，若作攝，得入一心。根本但內淨受喜；特勝有觀慧，恒攝喜心。心作解脫者，此對三禪。根本之樂，猗喜遍身受，凡夫捨為難；特勝有觀慧，則無愛味，故言「解脫」。從心作喜至心作解脫，皆是心念處也。

The mind generating joy and the mind collecting itself: the former joy arose from the thirty-six substances, whereas here one directly generates joy with respect to the mind; thus we know it matches the second dhyāna. The Mahāsaṃnipāta explains that the second dhyāna has only three factors, lacking internal clarity. Now generating joy in the mind seems similar in sense to this. As for collecting: if joy stirs, it scatters; if one collects it, one attains entry into one-pointedness of mind. The fundamental has only internal clarity and experiencing joy; the extraordinary possesses the wisdom of contemplation and constantly collects the joyful mind. The mind generating liberation matches the third dhyāna. The pleasure of the fundamental is an attached joy experienced throughout the whole body, which ordinary persons find difficult to relinquish; the extraordinary possesses the wisdom of contemplation and is thus free from craving and attachment, hence it is called "liberation." From the mind generating joy to the mind generating liberation, all are the smṛtyupasthāna of mind.