Full-lotus posture makes it easy to enter samadhi.
Full-lotus posture is another name for the vajra posture just described. By placing our left foot on top of our right thigh and then placing our right foot on our left thigh, we achieve full-lotus position. The left foot belongs to yang while the right foot belongs to yin. When assuming this meditation posture, the left foot, which is yang, is placed first, so that it is under, while the right foot, which is yin, is placed second on top. This balance of yin and yang can be seen in the taiji symbol, which depicts the absolute, from which comes primal beginning, and then from primal beginning, the two primary forces of yin and yang are shown symbolically as intertwined fish.
For those who prefer, it is also acceptable to put the left foot below and the right foot on top. The Dharma is not fixed and can be adapted according to a person’s preference. It is not necessary to attach rigidly to the particulars of the sitting posture. I am teaching the classic method, where the left foot goes on the right thigh and the right foot on the left thigh. It is not a fixed rule that you have to sit in this position. In conclusion, lotus posture facilitates entry into samadhi. It makes it much easier to do so. If we could enter samadhi while walking, it would not be necessary to sit. The state of samadhi is devoid of false thoughts. When the mind does not entertain a single thought, then it will not be defiled by even a single speck of dust. When our mind entertains no thoughts and is not defiled by even a speck of dust, then we can continue to develop our skill while walking, standing, sitting, and reclining. At that point, we will not be limited to the sitting posture alone.