Nine at the second position is yang-firm, responded to by Six at the fifth position. Thus, with yang-firm talent below, it manages the yin-yielding affairs of the superior above; hence the image of a son managing the mother's decay is taken.
A firm and yang minister aiding a yielding and weak sovereign shares a similar meaning. The second line belongs to the Xun trigram and dwells in yielding compliance, embodying abundant compliance—this is the way to manage a mother's decay.
In a son's relation to his mother, he should guide her with gentle compliance so that she aligns with righteousness; causing her to fail or fall into ruin through disobedience is the son's fault. Following along with ease and gentle persuasion—how could there be no way?
Speaking in terms of a woman, her yin-yielding nature is evident; if one asserts one's own firm and yang way to abruptly correct and oppose her, affection will be wounded and great harm done—how could one gain entry?
It lies in humbling oneself, lowering one's will, and compliantly supporting her so that her person is rectified and affairs are ordered, and nothing more.
Therefore it is said, 'One must not be persevering,' meaning one should not stubbornly insist on exhausting the way of unyielding rectitude; acting thus constitutes the middle way. How could one compel her to achieve lofty feats?
If, toward a yielding and weak ruler, one devotes utmost sincerity and loyalty to bring him to the middle way, that is sufficient; how could one drive him to great undertakings?
Even with the sagacity of the Duke of Zhou aiding King Cheng, King Cheng was not exceedingly weak, yet the Duke could only enable him to be King Cheng—preserving the dynasty without losing the Dao was enough; he certainly could not make him accomplish the deeds of Fuxi, the Yellow Emperor, Yao, or Shun.
The second line belongs to the Xun trigram and attains the center; being able to comply while attaining the middle way accords with the meaning of 'one must not be persevering,' perfectly capturing the way to manage a mother's decay.