菩薩瓔珞本業經 2.6

2.6

"Therefore, O Son of the Buddha! Advancing from the mind of coronation into the stage of the empty dharma-nature of the five aggregates, one also practices the eighty-four thousand prajñāpāramitās; thus these are called the middle ten practices, O Son of the Buddha! Therein, initially entering into the emptiness of phenomena, not overthrown by non-Buddhist heterodox treatises, and entering the correct stage, it is called the 'practice of joy.'