Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 34

Chapter 34.—Of God’s Clemency in Moderating the Ruin of the City.

And that you are yet alive is due to God, who spares you that you may be admonished to repent and reform your lives.  It is He who has permitted you, ungrateful as you are, to escape the sword of the enemy, by calling yourselves His servants, or by finding asylum in the sacred places of the martyrs.

It is said that Romulus and Remus, in order to increase the population of the city they founded, opened a sanctuary in which every man might find asylum and absolution of all crime,—a remarkable foreshadowing of what has recently occurred in honor of Christ.  The destroyers of Rome followed the example of its founders.  But it was not greatly to their credit that the latter, for the sake of increasing the number of their citizens, did that which the former have done, lest the number of their enemies should be diminished.