Contemplative practice (vipaśyanā-caryā) is like a hitching post for tethering the horse of the manas.

Lantian 1's contemplative practice (vipaśyanā-caryā) journal: Sitting down, I adopted active deep abdominal breathing—inhaling to the maximum, pausing briefly, then exhaling to the maximum, and pausing briefly again. After about half an hour of deep breathing, I could feel a distinct sensation of qi, after which I slowly transitioned to natural abdominal breathing. 

Following the text of the Satipaṭṭhāna Sūtra, I no longer thought about anything else during the breathing, constantly maintaining awareness of the breath. Only then did I discover that thoughts would pop up from time to time, and sometimes it was truly difficult to control and keep them from arising. The main content of these thoughts was the faces of people I had recently been in contact with over the past few days—the more contact I had with someone, the more intensely their face appeared. Now I understand why the ancients all avoided crowded places when cultivating. This may be what is called the manas' characteristic of grasping and habituation. Only toward the end of the sitting did my mind gradually begin to feel somewhat clear. 

Today's meditation felt mediocre; the mind was not very calm. During the sitting, the faces of people I frequently interact with inexplicably flashed up, and the natural abdominal breathing was not very deep and long. 

Assessment: This fully demonstrates the imputed nature (parikalpita-svabhāva) of the manas, and demonstrates the manas' characteristic of grasping—its attachment to states that have been previously encountered. Whether meaningful or meaningless, it pays attention to and clings to them all, refusing to let the mind rest. To subdue this wild horse, you must tether it to the pillar of the breath. At first, He will jump and thrash about wildly, but over time, He will grow accustomed to it and calm down, and begin to pay attention to and examine the pillar and the scenery around the pillar. Then things become easy to handle. This is called getting onto the Path.