Sailing along the river is a gift: someone will help you find ways to help you, which is a metaphor for helping others;
The right man just plans the whole plan: if you want to find someone, you have to have a comprehensive method, which means you have to be prepared;
You don't have to go anywhere else for advice. It's a metaphor. Fate comes when it comes, but it doesn't arrive when it doesn't.
The so-called signing is nothing more than classical Chinese, insisting on writing something that everyone can understand, so that ghosts can't understand it.
In the final analysis, it is also nonsense and ambiguous.