This clause is related to the obstacle, or obstruction, of passion. That obstruction has its root in the defilement of confusion, or ignorance, which manifests as mistaking the impermanent for the permanent, the ugly for the beautiful, and suffering for happiness. It is the way of people of mundane interests. The Bodhisattva, however, whose conception has been clarified through Prajna has been liberated to a great extent from that obstruction.