The fourth line returns to the image of horses in retreat, but the setting has changed from the second line's uncertain approach to a more deliberate courtship. Legge's rendering gives the horses of the chariot appearing in retreat, and the fuller traditional reading attached to this line describes a search for marriage alliance in which advancing now brings good fortune, the hesitation of retreat giving way to the advantage of a renewed approach rather than an abandoned one.
This line opens the upper trigram Kan, water, the trigram associated with danger and difficulty that gives the hexagram its overhanging obstacle. Occupying the lowest place of that trigram, the line marks a first test of whether the patience built through the lower trigram Zhen can be carried into more exposed territory, where the surrounding difficulty is felt most directly. The horses' hesitation reflects that exposure honestly, but the line's judgment is that hesitation here should be answered by continued advance rather than by giving up the pursuit.
Chinese commentary tradition often reads this line together with the second, both built from the same image of horses seeming to retreat, but distinguishes their outcomes: where the second line counsels patient waiting for a suitor not yet understood, the fourth line counsels active pursuit of a union whose rightness is now clearer. The difference marks real progress across the hexagram, from uncertain retreat to confident advance toward the same essential goal.