The realm of Foundation Establishment comprised three minor stages: qi sea generation, great and small as one wishes, and tortoise and snake embracing each other.
"Qi sea generation" needed little explanation. After the nine returns of qi refining, one planted a mystic root and refined a qi sea, thereby attaining this stage.
Cultivating True Qi was equivalent to laying the first foundation stone of longevity through the Great Dao.
The meaning of Foundation Establishment.
Had derived from this-
As for the second stage of Foundation Establishment, "Great and small as one wishes."
This stage required circulating True Qi again, slowly refining it into the fleshly body, little by little.
This undertaking severely tested a cultivator's ability to shift and transform True Qi. Only by wielding True Qi as lightly as though something heavy weighed nothing, releasing and withdrawing it at will, could one begin the gradual process.
If one rashly pressed ahead with brute force and made even the slightest misstep while practicing.
One would end up riddled with internal injuries, one’s Origin True Essence depleted. The risks were immense.
Yet although this stage required braving danger, attaining it also brought tremendous benefits.
It could nourish the blood and vital energy and strengthen the body.
True Qi nourished the flesh, and the flesh in turn nourished True Qi.
This was precisely the crux of the two joining together, the formless and the formed transforming into one another, the Dao body having no fixed basis, and the Dao uniting all as one!
As for why this stage was called "great and small as one wishes."
It meant not only that cultivators who attained it could wield and refine their True Qi at whatever scale they wished, without the slightest obstruction.
They could also shift the positions of their bones a little,