With mild innate afflictive obstruction (kleśāvaraṇa), meditative concentration is easily aroused

Lantian's Contemplative Practice Journal: Day 46 of Sitting Meditation: Observing the Breath In the evening, I sat down and did ten deep breaths, then observed the breath at the nose, gradually entering abdominal breathing. During this period, in the initial stage of abdominal breathing, the contraction of the abdominal muscles when inhaling was no longer so intense, but today the abdomen contracted strongly on the exhale, and the dantian was very hot during breathing. I continuously observed the breath at the nose without moving my thoughts elsewhere. 

After sitting for about half an hour, I felt the qi mechanism about to arise upward. Following my master's teaching, I let it happen naturally without stopping it, and I felt the qi mechanism instantly reach the chest, but it did not rise further. The entire area below the chest felt like an electric current passing through, and it vanished in an instant. I continued observing the breath at the nose; it was still abdominal breathing at this point. After another ten minutes or so, the qi mechanism surged upward again, and both ears rang simultaneously for a moment. The pores of my entire head and face stood on end, tingling and numb. The sensation quickly subsided. A slight sweat appeared on my front and back and on my abdomen. The deep breathing stopped. Looking at the clock, there were still ten-plus minutes left, so I deliberately did deep breathing until the end of the sitting. 

In the morning, I sat down and did ten deep breaths, then observed the breath at the nose, and soon entered abdominal breathing. This morning the dantian area was also very hot, especially when inhaling—I could feel the airflow entering the dantian from the upper abdomen like a stream of heat. Sometimes with one inhalation, I could feel the tops of my thighs were cool, as if cool air were entering through the thighs. After sitting for about half an hour, I again felt the qi mechanism surging upward. This time it was slower and not as intense; it surged up to the chest and head and would not go down. The qi distension in the chest caused the breath to become short, and the head also felt somewhat swollen but not very pronounced. This lasted ten minutes. When I placed my attention at the dantian, the above discomforts slowly dissipated, the breathing became smooth, both shoulders sank down, and the abdomen felt soft and comfortable. 

Assessment: The emptier the mind, the faster and longer the qi mechanism arises, and the deeper the meditative concentration (samādhi). For those obstructed by innate afflictive obstruction (kleśāvaraṇa), the qi mechanism does not arise easily, and even when it does arise, it quickly falls away. In the future, when the first dhyāna arises, there will be a similar arising of the qi mechanism. The emptier the mind and the lighter the innate afflictive obstruction, the faster and more deeply the qi mechanism arises, the more it can pervade the whole body, the longer it can last, and the deeper the meditative concentration. What is called innate afflictive obstruction is that the mind has clinging thoughts—clinging to the body and clinging to self, dwelling on many dharmas, with ceaseless grasping at conditions, taking all worldly dharmas as real and refusing to let them go.