This law forbids only the naturalization of those against whom it is directed. It does not forbid their dwelling in the land; and seems to refer rather to the nations than to individuals. It was not understood at any rate to interdict marriage with a Moabitess; compare Ruth 1:4; Ruth 4:13. Ruth however, and her sister were doubtless proselytes.

An Ammonite or Moabite - These nations were subjected for their impiety and wickedness, (see Deuteronomy 23:4 and Deuteronomy 23:5), to peculiar disgrace, and on this account were not permitted to hold any office among the Israelites. But this did not disqualify them from being proselytes: Ruth, who was a Moabitess, was married to Boaz, and she became one of the progenitors of our Lord.

Even to their tenth generation - That is, for ever, as the next clause explains; see Nehemiah 13:1.

An Ammonite or Moabite shall not enter into the congregation of the Lord,.... Or marry an Israelitish woman, as Jarchi, and so the Targum of Jonathan,"the male Ammonites and Moabites are not fit to take a wife of the congregation of the Lord;''for the Jews restrain this to men, because it is, as Aben Ezra observes, an Ammonite, not an Ammonitess, a Moabite, not a Moabitess; they allow that females of those nations might be married to Israelites, that is, provided they were proselytesses, as Ruth was (m):

even to their tenth generation, shall they not enter into the congregation of the Lord for ever; that is, not only to the tenth generation, but for ever; and this law was understood as in force in Nehemiah's time, which was more than ten generations from the making of it; though now, as these nations are no more a distinct people, they suppose it is no longer binding (n).

(m) Misn. Yebamot, c. 8. sect. 3.((n) Misn. Yadaim, c. 4. sect. 4.

Also no Ammonite or Moabite was to be received, not even in the tenth generation; not, however, because their forefathers were begotten in incest (Genesis 19:30.), as Knobel supposes, but on account of the hostility they had manifested to the establishment of the kingdom of God. Not only had they failed to give Israel a hospitable reception on its journey (see at Deuteronomy 2:29), but they (viz., the king of the Moabites) had even hired Balaam to curse Israel. In this way they had brought upon themselves the curse which falls upon all those who curse Israel, according to the infallible word of God (Genesis 12:3), the truth of which even Balaam was obliged to attest in the presence of Balak (Numbers 24:9); although out of love to Israel the Lord turned the curse of Balaam into a blessing (cf. Numbers 22-24). For this reason Israel was never to seek their welfare and prosperity, i.e., to make this an object of its care ("to seek," as in Jeremiah 29:7); not indeed from personal hatred, for the purpose of repaying evil with evil, since this neither induced Moses to publish the prohibition, nor instigated Ezra when he put the law in force, by compelling the separation of all Ammonitish, Moabitish, and Canaanitish wives from the newly established congregation in Jerusalem (Ezra 9:12). How far Moses was from being influenced by such motives of personal or national revenge is evident, apart from the prohibition in Deuteronomy 2:9 and Deuteronomy 2:19 against making war upon the Moabites and Ammonites, from the command which follows in Deuteronomy 23:8 and Deuteronomy 23:9 with reference to the Edomites and Egyptians. These nations had also manifested hostility to the Israelites. Edom had come against them when they desired to march peaceably through his land (Numbers 20:18.), and the Pharaohs of Egypt had heavily oppressed them. Nevertheless, Israel as to keep the bond of kindred sacred ("he is thy brother"), and not to forget in the case of the Egyptians the benefits derived from their sojourn in their land. Their children might come into the congregation of the Lord in the third generation, i.e., the great-grandchildren of Edomites of Egyptians, who had lived as strangers in Israel (see at Exodus 20:5). Such persons might be incorporated into the covenant nation by circumcision.

An Ammonite or Moabite shall not enter into the congregation of the LORD; even to their tenth generation shall they not enter into the congregation of the LORD for ever:

23:3 For ever - This seems to note the perpetuity of this law, that it should be inviolably observed in all succeeding ages.

3. even to the their tenth generation shall they not enter-Many eminent writers think that this law of exclusion was applicable only to males; at all events that a definite is used for an indefinite number (Ne 13:1; Ru 4:10; 2Ki 10:2). Many of the Israelites being established on the east side of Jordan in the immediate neighborhood of those people, God raised this partition wall between them to prevent the consequences of evil communications. More favor was to be shown to Edomites and Egyptians-to the former from their near relationship to Israel; and to the latter, from their early hospitalities to the family of Jacob, as well as the many acts of kindness rendered them by private Egyptians at the Exodus (Ex 12:36). The grandchildren of Edomite or Egyptian proselytes were declared admissible to the full rights of citizenship as native Israelites; and by this remarkable provision, God taught His people a practical lesson of generosity and gratitude for special deeds of kindness, to the forgetfulness of all the persecution and ill services sustained from those two nations.

23:1-8 We ought to value the privileges of God's people, both for ourselves and for our children, above all other advantages. No personal blemishes, no crimes of our forefathers, no difference of nation, shuts us out under the Christian dispensation. But an unsound heart will deprive us of blessings; and a bad example, or an unsuitable marriage, may shut our children from them.