"To come hat in hand" is one thing that a proud,
independent man with a feeling for his own personal value,
will not do --- not if he can help it.
The phrase means to beg, to ask for a "handout",
for something that you cannot claim as your own. You ask
for it as an act of charity.
But there are people who refuse to give you what rightfully
belongs to you. They will do so only if you beg for it like
a dog that stands up on its hind legs and barks for a piece
of meat. Such people are called "high-handed",
too sure of themselves, arrogant and over-proud.
Just the opposite it the man who gives with a glad and
willing hand, not only what is rightfully yours, but even
more, something extra. There is an old saying to describe
such a person. He is a man who "does not let his left
hand know what his right hand is doing". He gives freely,
without thinking about it too much.