Thunder bursting from the earth in spring: Yù is enthusiasm — the rousing energy that sets people and projects in motion, the power of inspiration to organize effort as music organizes feeling.
Its condition is that enthusiasm must move along the line of least resistance — aligned with what people genuinely feel and the time genuinely allows. Then helpers can be appointed and armies set marching. Enthusiasm that merely brags, or waits for others to supply it, misfires.
問Yù brings music into a relationship — shared excitement, plans that lift both hearts. Its counsel distinguishes true enthusiasm from its counterfeits: the boasting first line and the dependent third, waiting for the other person to generate all the joy. Real shared enthusiasm springs from what both genuinely feel; find that, and the relationship moves like a dance.
Professionally, Yù is the hexagram of momentum and morale — launching with inspiration, rallying a team, the leader as conductor. Its craft is reading what people actually respond to and building motion along that grain. Beware deluded enthusiasm sustained past its evidence; the final line honors those who can wake even after the song ends.
Inwardly, Yù asks what genuinely rouses you — and warns against both borrowed excitement and enthusiasm as performance. The second line is its compass: firm as a rock, reading the seeds of things, moving the moment clarity comes without waiting a whole day. Joy anchored in judgment is this hexagram's mature form.
A line speaks only when it is a changing line in your own casting.