Modesty opens at its lowest point with a doubling rather than a beginning. Legge's translation of the first line describes a superior man who adds humility to humility, and states that even the great stream may be crossed on that footing, with good fortune following. Humility is not introduced here as a correction of some earlier arrogance. It is already present, and the line deepens it further, which is what makes the claim practical rather than merely moral.
The stroke is the bottom of the lower trigram Gen, the mountain, and Modesty is the hexagram that sets a mountain beneath the earth instead of above it. Height concealed under level ground is the whole picture, and this line is where the concealing starts. A yielding stroke in an odd place counts as incorrectly placed by the positional rule, yet the mismatch costs nothing, since a line whose entire virtue is lowness gains nothing from a position that would raise it.
The great stream is the classical figure for an undertaking whose outcome cannot be controlled once entered. What the line offers is not a way of controlling it but a way of meeting it unencumbered. Nothing at this station is owed, guarded or displayed, and it is that emptiness of claim rather than any strength the line holds which the text credits with bringing its subject safely to the far bank.