Six at the beginning means

A superior man modest about his modesty

May cross the great water.

Good fortune.

A dangerous enterprise, such as the crossing of a great stream, is made much more difficult if many claims and considerations have to be taken into account. On the other hand, the task is easy if it is attended to quickly and simply. Therefore the unassuming attitude of mind that goes with modesty fits a man to accomplish even difficult undertakings: he imposes no demands or stipulations but settles matters easily and quickly. Where no claims are put forward, no resistances arise.