In chapter 13 of up from slavery why did he use the parable of the parched sailors searching for water who are told Cast down your bucket where you are?

In 'Up From Slavery,' the parable of the parched sailors was used to illustrate that efforts for change should be tackled close to home before venturing out in the world. Washington believed that it was important to try to cultivate the relationship between the southern white man, who many blacks viewed as impossible to communicate with, instead of attempting communication with the northern white, who many believed would be automatically receptive.