Legge's translation of the first line reads that the subject is like grass pulled up, bringing with it the stalks connected to it by their roots, and that advance on the part of its subject will be fortunate. The image is agricultural and communal at once, one clump of grass never rising alone, since pulling on any single stalk lifts every stalk still bound to it by a shared root.
The line sits at the base of Qian, the lower trigram of Heaven, in the lowest and correctly yang seated place, the point at which Peace begins its ascent of three unbroken yang lines advancing together toward the receptive earth above. Nothing in the hexagram's Judgment describes solitary striving; the great is said to come and the small to go, and the first line shows exactly how that arrival happens, not as one figure's isolated advance but as an entire company of connected, similarly disposed lines rising as one body.
Read against Peace's whole structure, heaven and earth in communication, the first line establishes the pattern the rest of the lower trigram will continue, advance here draws its strength from connection rather than from any single line's individual merit, and it is precisely that mutual support which the Judgment's good fortune depends on from the outset.