The topmost line is where the hexagram's nourishment actually comes from. Legge's translation describes the subject from whom the nourishing of others proceeds, notes the peril attaching to such a position, and gives good fortune together with advantage in crossing the great stream. The Great Symbolism adds that there is great cause for congratulation. After five lines occupied with seeking, refusing or misdirecting nourishment, the sixth is the one that supplies it.
The stroke is strong and stands at the top of the upper trigram Gen, mountain, forming the upper lip of the mouth the whole figure draws. By the ordinary rule a yang line in this even place is incorrect, and the topmost position is usually read as being past the seat of power rather than in it. Neither reading diminishes the line here, because the subject of the hexagram is not authority but supply, and the strong stroke at the summit is what the yielding fifth line beneath draws on in order to provide for everyone below.
The awareness of peril is the condition attached, and it is not decorative. Being the source on which others depend is treated by the text as a dangerous station, because failure at this point is not private. The line receives its good fortune, and its permission to cross the great stream, precisely because it holds that danger in view. The venture forbidden to the fifth line is opened to the sixth for the plain reason that here the resources being staked are genuinely its own.