St. Thomas Aquinas, treating the political community in the light of both Aristotle’s Politics and the Mosaic Law, noted that a nation may distinguish among foreigners according to their readiness to live under its law and share its common good. The Exodus and the statutes given by God at Sinai and in the wilderness supply the biblical precedent for that distinction.
In Exodus 12, as Israel prepares to depart Egypt, the Lord commands Moses and Aaron that any sojourner who wishes to keep the Passover with the people must first be circumcised; an uncircumcised man may not eat of it. The statute concerns those who seek to join the covenant community, not every foreigner present in the land.
The Lord then explicitly instructs:
“The same law shall be to him that is born in the land, and to the proselyte that sojourneth with you.” (Exod. 12:49)
The Lord establishes two things here: one law for native and sojourner, and a concrete condition of entry for those who wish to share the sacred meal of the people. Admission is not automatic. It requires a deliberate act of joining and the rite that marks membership; i.e., assimilation. The same principle of a single law governing both native and stranger is repeated several times throughout the wilderness years (see Lev. 24:22; Num. 15:15).
The wilderness generation itself illustrates the requirement of fidelity. As they journey through the desert, the Israelites repeatedly grumble against God and wish for the relative safety of Egypt. Despite God’s repeated signs and constant provision, they continue to prefer Egypt and refuse to keep faith in Him. At Kadesh, on the cusp of arriving in the Promised Land, the Israelites send spies into the land, who come back with a fearful (and false) report about the land and the people who dwell in it; once again, on the very verge of entering the Promised Land, the Israelites resolve to go back to Egypt (Num. 13, 14).
God condemns them to wander in the desert until the entire generation that has come out of Egypt passes away.
“But yet all the men that have seen my majesty, and the signs that I have done in Egypt, and in the wilderness, and have tempted me now ten times, and have not obeyed my voice, shall not see the land for which I swore to their fathers, neither shall any one of them that hath detracted me behold it.” (Num. 14:22–23)
The Lord then declares that none of that generation who saw His works and yet disbelieved will enter the land of Canaan, except Joshua and Caleb. Even Moses and Aaron were barred at Meribah.
The Lord prepares a people able to receive the Promised Land. To do so, He had to exclude those whose attachments remained with Egypt. The criterion is not blood alone, but readiness to keep the covenant.
On the plains of Moab, shortly before entering the Promised Land, Moses gives final commands to the Israelites, including explicit limits on which peoples may enter the assembly of the Lord:
“The Ammonite and the Moabite, even after the tenth generation shall not enter into the church of the Lord for ever: because they would not meet you with bread and water in the way, when you came out of Egypt: and because they hired against thee Balaam, the son of Beer, from Mesopotamia in Syria, to curse thee.” (Deut. 23:3–4)
“Thou shalt not abhor the Edomite, because he is thy brother: nor the Egyptian, because thou wast a stranger in his land. They that are born of them, in the third generation shall enter into the church of the Lord.” (Deut. 23:7–8)
The Ammonites and the Moabites are excluded in perpetuity for concrete acts of hostility toward God and His people. Edom and Egypt, though related by kinship or prior hospitality, are admitted only in the third generation. The delay ensures that those who enter the assembly know no other community. Admission is possible, but it is neither immediate nor unconditional.
Throughout the Law, the sojourner is bound by the same statutes as the native (Exod. 12:49; Lev. 24:22; Num. 15:15). Full membership in the assembly, however, requires more than residence. It requires the rite of entry where the sacred life of the people is concerned, and, in the cases governed by Deuteronomy 23, a generational gap that secures cultural and covenantal continuity.
The ceremonial and civil provisions of the Mosaic Law are no longer binding on the Church. Nevertheless, they hand down through the generations a consistent principle: the stranger who dwells among the people is subject to the same law; full incorporation into the community is not automatic but requires deliberate assimilation and a measured delay. The duty of hospitality is ordered by the good of the community that receives.
Nations may still distinguish, regulate, and require that those who seek permanent membership share the law and the life of the people. Charity with order is the pattern the Law itself exhibits.
