A few random quotes from hundreds of others:

“When the Most High gave the nations their inheritance, when He separated the sons of man, He set the boundaries of the peoples according to the number of the sons of Israel.” – Deuteronomy 32:8

“He made from one man every nation of mankind to live on all the face of the earth, having determined their appointed times and the boundaries of their habitation.” – Acts 17:26

Aquinas

“God holds first place, for He is supremely excellent, and is for us the first principle of being and government. In the second place, the principles of our being and government are our parents and our country, that have given us birth and nourishment. Consequently man is debtor chiefly to his parents and his country, after God. Wherefore just as it belongs to religion to give worship to God, so does it belong to piety, in the second place, to give worship to one’s parents and one’s country [i.e., one’s people]. The worship due to our parents includes the worship given to all our kindred, since our kinfolk are those who descend from the same parents.” – Summa Theologica, Volume 3, Part 2, Second Section

Luther

“...each town should support its own poor and should not allow strange beggars to come in, whatever they may call themselves, pilgrims or mendicant monks. Every town could feed its own poor; and if it were too small, the people in the neighbouring villages should be called upon to contribute. As it is, they have to support many knaves and vagabonds under the name of beggars….” – Address To The Nobility Of The German Nation

Calvin

“The sweetness of their native soil holds nearly all men bound to itself.” – Commentary on Genesis 12:1

“Delightful to every one is his native soil, and it is also delightful to dwell among one’s own people . . . all his relatives and the nation from which he sprang.” – Commentary on Jeremiah 9:2

“Among men, in proportion to the closeness of the tie that mutually binds us, some have stronger claims than others.” – John Calvin on Matthew 10:37

Matthew Henry

“The times are perilous when men will not be held by the bonds either of nature or common honesty, when they are without natural affection, and truce-breakers, v. 3. There is a natural affection due to all. Wherever there is the human nature, there should be humanity towards those of the same nature, but especially between relations. Times are perilous when children are disobedient to their parents (v. 2) and when parents are without natural affection to their children, v. 3. See what a corruption of nature sin is, how it deprives men even of that which nature has implanted in them for the support of their own kind; for the natural affection of parents to their children is that which contributes very much to the keeping up of mankind upon the earth. And those who will not be bound by natural affection, no marvel that they will not be bound by the most solemn leagues and covenants.” – Commentary on 2 Timothy 3:3

Lancelot Andrews

“In the ordering of our Love…we are to respect the conjunction by nature or grace in the duties of Love which we freely perform…We owe not so much to those persons with whom we have no such Conjunction. Thus, we should prefer a faithful man before an infidel, because in the one there is only the image of God by nature, in the other it is both by creation and regeneration…And among the faithful, we should rather do good to those of our own country, than to Strangers, because beside the bonds of Religion, there is also a second bond of proximity and cohabitation, and among them to our acquaintance before those that are unknown to us, because we have an easier entrance unto them to do them good by persuasion, etc. And among