Legge's translation of the second line describes a subject who can bear with the uncultivated, who will cross the great river without a boat, who does not forget those who are distant, and who sets aside partisan attachments, all of which together the commentary reads as proof that this subject acts in accordance with the due Mean. Four distinct qualities are named at once, tolerance, boldness, breadth of concern, and impartiality, and each answers a different way that a time of peace might otherwise narrow into complacency.
Nine in the second place holds the center of Qian, the lower trigram, and its centrality is what the commentary points to directly as the reason these four qualities cohere rather than pulling against each other. Bearing with the uncultivated without becoming careless, crossing dangerous ground without waiting for safer means, remembering what is far away without neglecting what is near, and setting aside faction without losing personal conviction, all require exactly the balance a central position provides.
Where the first line showed advance through connection to similar companions, the second line shows the different, harder discipline of holding a settled peace open rather than letting it curdle into narrowness, favoring the near over the far or one faction over another. Legge's text treats this breadth as the substance of the due Mean itself, not a compromise between extremes but a single, central course wide enough to include them all.