"Rice ears droop under the weight of rice which make a man look like he bows deeply."
The meaning is that the more a man forms character, the less he assumes an air of importance.
There are many people who look down on others and get arrogant as they become rich, raise their position or win an election.
They lose friends when they become poor and lose their position.
A man can't live without the support of many friends.
It is important to stay humble.