Six at the top is divinatorially the hexagram's most severe line, and a reading landing here tells the querent that a difficulty long endured has reached its most acute point. The image of horses obliged to retreat and tears falling in streams offers no relief within the line itself, echoing the second and fourth lines' retreating horses but here without either the union the second line eventually promises or the advantage the fourth line's renewed advance secures.
The line's position, topmost in the upper trigram Kan with nothing above it to answer to and no ruling seat beneath it to anchor its conduct, is read in commentary tradition as the accumulated weight of every difficulty the hexagram has carried from its very first line, arriving here with nowhere further to be deferred. A reading landing on this line often marks a genuinely difficult culmination, a trial, loss, or setback that has been building throughout a longer process now reaching its hardest point.
Divinatory tradition nonetheless reads the line as an endpoint rather than a permanent condition, since the hexagram itself supplies no further line beyond it: difficulty pressed to its true extremity, in this reading, exhausts rather than perpetuates itself. The counsel offered is unglamorous but real, that endurance through this specific extremity, rather than any clever action, is what the line asks of the querent, since the hexagram's own structure guarantees that what follows a beginning this difficult is, at minimum, no longer its beginning.