Nine in the third place, as a changing line, cautions against assuming a peace already achieved needs no further tending. The querent is reminded that no level place lacks its slope and no departure its eventual return, and the line's promise, no error for one who remains firm and correct through the ordinary difficulty a settled time still contains, treats vigilance without anxiety as the correct response rather than either complacency or dread.
Flipping this line changes the lower trigram from Qian to Dui, Lake, giving Kun over Dui, the hexagram called Approach. The natural, cyclical caution of the third line, level ground followed by slope, gives way on the far side of change to a hexagram of advancing influence and growing favor, joy rising to meet the receptive earth rather than heaven's full strength doing so. The movement suggests that accepting the small hardships of a settled peace honestly, rather than resisting them, is itself what allows a gentler, more particular kind of advance to follow.
Within Peace's arc, the third line stands at the exact boundary between the lower trigram's rising strength and the upper trigram's receptive yielding, the last position before the hexagram's character shifts from active ascent to something more delicately maintained. A reading landing here suggests the present moment asks for firm, ungrieving patience through minor setbacks, not proof that the peace itself has failed.