Shallow Concentration and Deep Concentration

Question: In meditation, I found that when the mind takes the Image-Only Object as its object, the samādhi is deeper than when it takes the five sense objects as its object. What is the reason for this? 

Answer: When taking the five sense objects as objects, the six consciousnesses are all active—the eye consciousness wants to see, the ear consciousness wants to hear, the nose consciousness wants to smell, the tongue consciousness wants to taste, the body consciousness wants to touch, and the mind consciousness wants to know. With such bustle and confusion, it is naturally not easy to attain samādhi; even if there is samādhi, it is only shallow samādhi. But after the five consciousnesses are sealed off and bound, only the perception of the solitary mental consciousness remains, which can discern and know with greater concentration, so naturally it is easier to enter samādhi. Once samādhi is entered, it may be relatively deep. When the solitary mental consciousness is also restricted, the samādhi becomes even deeper. The fewer consciousnesses participating in discernment, the deeper the samādhi; the fewer the objects discerned, the deeper the samādhi. Therefore, in the deepest cessation attainment (nirodha-samāpatti), there is no discernment by the six consciousnesses—only the manas alone carries on a relatively slight discernment. When the power of meditative concentration is insufficient and very shallow, do not engage in contemplative practice (vipaśyanā-caryā); the moment you contemplate, the mind becomes scattered. When contemplation cannot be sustained, focus single-mindedly on cultivating samādhi and refrain from contemplating for the time being. When the power of meditative concentration is somewhat deeper, then contemplate, and the results will be better. The methods of practice should be applied with flexibility—treat each specific situation on its own merits, and do not generalize.