Zhuo qi gui xin.
Turbid qi goes to the heart.
This statement is usually interpreted to mean that the turbid part of the clear goes to or gathers in the heart where it becomes the blood. To understand this concept, we must know that, just like yin and yang, clear and turbid each can be subdivided into clear and turbid. Thus the clear of the clear goes to the lungs to become the qi, while the turbid of the clear goes to the heart to become the blood.
- Statements of Fact in Traditional Chinese Medicine, by Bob Flaws