In common language, earth is mother. That is why we call it 'mother earth'. Just like mother performs so many roles in her life, and bears all the burden of a household and family, similarly earth bears all the burden of the people on it.
THERE IS is an example in this context: there was a person who was very kind to others, and used to help the poor and was always ready to help in all respects, like clothing, shelter and food. He also donated his piece of land to his sons, and in the remaining land area he installed wells, residing places etc. for the needy ones. He established a unique example of serving the people.
One day he went to Gautam Budha, and sought his preaching, and as a result of that, he decided to donate his whole life to spread the virtues of truth non-violence all over. Gautam Budha asked him: "Despite leading a homely life, how can you do that? you are a rare example to illustrate the qualities of a good human being. I have seen many people who get entangled in the desires of material world, and forget about others". After hearing this he returned to his home, and thought that why does not he donate his land and everything for the abode of Gautam Budha. But then another thought came to his mind: how can he do that? Who gives his mother earth to others? Then he decided that he will not do that, but keep on helping others.