The second line complicates the difficulty of the first with a scene of apparent retreat. Legge renders the subject as distressed and obliged to return, even the horses of the chariot seeming to retreat, an image of forward motion stalling and turning back on itself. The line's deeper reading, carried in traditional commentary, is that what first appears as plunder or threat approaching is in fact a suitor, someone seeking rightful union rather than harm, and that the appearance of danger is not the same as danger itself.
This is the central place of the lower trigram Zhen, a position commentary tradition treats as a seat of genuine capacity even while movement itself remains obstructed. The horses seeming to retreat mirror the larger difficulty of the hexagram: thunder wants to move, but water above still hinders it, and the line shows a subject reading that hindrance correctly, choosing to wait rather than to force a meeting or a departure before the moment is ready.
Traditional commentary reads the line as counsel against misjudging appearances under pressure. What looks like an approaching threat at a moment of general difficulty may in fact be help, or a rightful match, arriving in a form the beginning's confusion makes hard to recognize. The line's resolution, that holding firm brings eventual union, depends on this correct reading: retreat here is not final defeat but a pause before the true approach is properly received.