How to Investigate the True Nature of the Activities of the Five Aggregates (pañca-skandha)

While pacing back and forth in the room pondering a problem, identify the activities of the five aggregates (pañcaskandha) at that moment and observe them clearly. What is the aggregate of form (rūpa) doing? Where is the aggregate of feeling (vedanā), and what state is it in? Which one is the aggregate of perception (saṃjñā), and what is it perceiving? How does the aggregate of formations (saṃskāra) operate, and where is it? What are the object-aspects that each of the six consciousnesses of the aggregate of consciousness (vijñāna) discerns?

Then, in meditative concentration (samādhi), slowly and deeply observe and contemplate their nature of arising, ceasing, and change—their impermanence—come to know their nature of suffering, and confirm their selflessness.