The second line supplies the hexagram's first image of renewal. Legge's translation describes a decayed willow that puts out shoots, and pairs it with a household example, an old husband who has a young wife, with advantage in every way. The botanical half of the image carries the structural reasoning. Shoots on a willow break from low on the trunk or from the root, so the new growth comes from beneath the old wood rather than from its crown, and that is precisely the relation this line has to the yielding stroke below it.
Strong and central in the lower trigram Xun, this stroke stands in an even place, which the ordinary rule counts as incorrect. In this hexagram the mismatch works in its favour. A time of excess is one in which strength has piled up in the middle while the ends have gone weak, and a strong line that turns downward to the weak line beneath it is drawing on the one thing the middle of the figure lacks. What the text approves is the direction of the attachment.
The household comparison is the Zhou text speaking in the terms of its own period, and its verdict rests on that period's assumptions about marriage, age and the bearing of heirs rather than on anything a modern reader would supply. Set down plainly, the text ranks this pairing as advantageous where it will rank the mirrored pairing at the fifth line as merely blameless. The willow explains the difference in terms the marriage framing does not: growth that starts at the root can become a tree.