Nine at the top is the cleanest reading in Retreat and its counsel is simply to finish. The line describes a withdrawal made in a noble way, advantageous in every respect, with the commentary noting that no doubt attends the course. A querent drawing it has usually already done the hard part and is looking for confirmation, and the confirmation arrives without the hedging that qualifies almost every other favourable line in the classic.
The position accounts for that. A strong stroke at the top of Qian stands at the greatest possible distance from the mountain below, past every entanglement the lower lines described, and the sixth place, which usually indicates having gone too far, means here only having gone far enough. Somebody in this position can afford generosity toward what they are leaving, and generosity at the point of departure is most of what the word noble is doing in the line.
When the line changes, the upper trigram Qian becomes Dui and the figure becomes Influence, King Wen 31, the mutual attraction of two parties who move toward one another. Read from the far end of a retreat that is a surprising destination and a fitting one. A departure completed without residue leaves the person free to be drawn toward something new, which is not available to anyone still arguing with what they left.