Only one law may apply

The foundation myth of the people of Israel begins in their being strangers in a strange land. They become enslaved and then they are extracted, which together sets in train a process that eliminates the ruling class of their oppressors, the Egyptian people. 

These three elements form the core myth of the foundation of the people. The enslavement defines the economic basis of the people – that autonomous, self-determination in one's productive life is crucial to the national identity of the people. The elimination of the ruling class defines the political basis of the people – that the ruling class of Israel is consecrated to a higher power. The deepest element, however, is the first one – that Jews were strangers in a foreign land. That element constitutes the primary value of the Children of Israel – that only one law may apply to all the inhabitants of the land, all the residents, be they of the national identity of the Israelite people or be they foreigners. 

To be kind and welcoming to the stranger is the fundamental virtue of Avraham and it is built into the most basic teachings of Moshe. Xenia transcends economics or politics. It defines the character of the people. A people graced by an abundance from God has to be focused on taking care of the others, the strangers, the unfortunates.