**Catechism2241 The more prosperous nations are obliged, to the extent they are able, to welcome the
foreigner in search of the security and the means of livelihood which he cannot find in his country of
origin. Public authorities should see to it that the natural right is respected that places a guest under
the protection of those who receive him.
Political authorities, for the sake of the common good for which they are responsible, may make the
exercise of the right to immigrate subject to various juridical conditions, especially with regard to the
immigrants' duties toward their country of adoption. Immigrants are obliged to respect with gratitude
the material and spiritual heritage of the country that receives them, to obey its laws and to assist in
carrying civic burdens.
For Context see Catechism of the Catholic Church
Exodus 23:9 "You shall not oppress a stranger; for you know the heart of a stranger, for you were strangers in the land of Egypt."