(For a short introduction to Philo, his family and their connections with Rome, see Philo, On the Embassy to Gaius 8-10.)

The treatise On Virtues is part of Philo’s Exposition of the Law, a series containing “a treatise on the creation, three extant Lives of biblical patriarchs, four books on Mosaic law, and two concluding treatises on virtues and rewards and punishments,” which Maren Niehoff considers as having been composed after Philo’s embassy to Rome (Niehoff, Philo of Alexandria, p. 7-8). On Virtues discusses four virtues: courage (andreia), repentance (metanoia), humanity (or benevolence, philanthrōpia), and nobility (eugeneia). It continues the last book of On the Special Laws, which ends with a reflection on justice. Despite its thematic organisation, it can therefore be considered as part of Philo’s exposition of the Mosaic Law, which, by contrast with the Allegorical Commentary, consists mainly in a non-allegorical exegesis of the Pentateuch.
The section “On Humanity” (Peri Philanthrōpias) has a strong apologetic dimension. Philo is trying to respond to the accusations of misanthropy raised against the Jews and their laws by authors like Apollonius Molon and Apion (on these anti-Jewish statements, see Josephus, Against Apion, especially II.148; Berthelot, Philanthrôpia judaica, p. 144-153). Apion was the head of the Alexandrian embassy to Rome after the events of 38 CE, and Philo was confronted to this enemy of the Jews in a very concrete way (for a presentation of the events of 38 and the embassy, see Philo, On the Embassy to Gaius 8-10).
In response to the charges of misanthropy, Philo argues that the Law of Moses is full of humanity or kindness (philanthrōpia). His strategy is to distinguish between different categories of beings that benefit from these humane ordinances. He demonstrates successively that the Mosaic Law prescribes philanthrōpia toward fellow Israelites (the “native-born,” autochthōnes, §§82-101), foreigners or new-comers (epēlytai/epēlytoi, who are in fact proselytes, §§102-104), metics or foreign residents (metoikoi, §§105-108), enemies (§§109-120), slaves (§§121-124), animals (§§125-147), and plants (§§148-160) (for a detailed analysis of Philo’s argumentation, see Berthelot, Philanthrôpia judaica, p. 265-300; Wilson, Philo of Alexandria: On Virtues, p. 205-340).
The section on the metoikoi, which is our focus here, is based on Deuteronomy 23:8b-9: “You shall not abhor any of the Egyptians, because you were an alien residing in their land (Heb. ger, Greek paroikos). The children of the third generation that are born to them may be admitted to the assembly (Heb. qahal, Greek ekklēsia) of the Lord” (NRSV). In ancient Jewish texts, verse 9 has been variously interpreted as referring to intermarriage, entrance into the Temple or participation in the Temple cult in one way or another, and conversion (see Cohen, The Beginnings of Jewishness, p. 248-252).
In accordance with this biblical passage, Philo actually discusses both the Hebrews’ situation as foreign refugees in Egypt (as xenoi rather than paroikoi, considering the use of the term xenodochos in §106) and that of the Egyptians as foreign residents (metoikoi) among the Israelites. Philo’s choice to refer to the Egyptians as metoikoi provides the Greek reader with a familiar notion. As Walter Wilson notes, “In most Greek cities, a legal distinction was observed between foreigners (xenoi) and metics, non-citizens permitted to reside and work in a city under certain conditions” (Philo of Alexandria: On Virtues, p. 256). Philo recalls allusively that the benevolent reception of the Egyptians among the Israelites is linked to the former’s decision to let the Hebrews settle in Egypt at the time of Joseph (to escape a drought in Canaan, according to Genesis 41:57, 43:1-2, 46:5-7), but he also insists that the Egyptians did not treat the Jews well (alluding to Exodus 1:8-14 and the story of the slavery in Egypt) (§§106-107). His rhetorical question—“What evil was there that the Egyptians neglected to inflict upon our nation, ever adding new evils to old with schemes contrived for the sake of cruelty?” (§107)—may indicate that On Virtues, or at least the section On Humanity, was written after the events of 38 CE and the Alexandrians’ attacks against the Jews. Even though it was the Greek citizens of Alexandria who provoked the riots, Philo insists that the despised Egyptians played a great role in them; he may even be suggesting that the Alexandrians involved in these attacks were in fact Egyptians (see Flacc. 17, 29; on Philo’s negative view of the Egyptians, see Berthelot, “The Use of Greek and Roman Stereotypes”; Niehoff, Philo on Jewish Identity and Culture, p. 45-74; Pearce, The Land of the Body, p. 54-80).
The contrast between the bad treatment reserved to the Hebrews by the Egyptians and the benevolent prescriptions of the Mosaic Law toward them serves to highlight the generosity of the Jewish laws. The Torah even allows the Egyptians to become part of the congregation (ekklēsia) of Israel, at least as far as the fourth generation of residents and their descendents are concerned (§108). Philo describes this integration as the fact of “crossing over to the politeia of the Jews” (metallaxasthai pros tēn Ioudaiōn politeian, §108), by which he means a proper conversion, that is, abandoning polytheism, joining in the cult of the true God and becoming a member of the people of Israel (see also Philo, On the Special Laws I.51-52; on the Jewish people/community as a politeia in Philo, see Carlier, La cité de Moïse, p. 129-171). Ultimately, the benevolence (philanthrōpia) shown by the Mosaic Law toward the Egyptians consists in the possibility of conversion, that is, of receiving “Jewish citizenship”. (Philo astutely refrains from discussing Deuteronomy 23:2-7, which excludes certain categories of people from joining the congregation of Israel.)
Philo’s choice of a biblical passage that refers to the integration of former enemies (be it through their descendents) to illustrate the Law’s philanthrōpia may be understood as a deliberate echo of Roman or pro-Roman discourses celebrating grants of citizenship to former enemies of Rome (Berthelot, “Judaism as ‘Citizenship,’” 125-127). Rome was praised for its philanthrōpia precisely because it granted Roman citizenship to foreigners, including former enemies (on grants of citizenship to former enemies, see Cicero, Pro Balbo 13.31, Livy, 8.13.15-16, Tacitus, Annals 11.24.1-4; on the interpretation of this policy as a manifestation of philanthrōpia, see especially Dionysius of Halicarnassus, Roman Antiquities 1.9.4, Dio of Prusa, To the Apameians, On Concord 41.9, and Josephus, Against Apion II.40: “Has not the benevolence (philanthrōpia) of the Romans ensured that their name has been shared with practically everyone, not only with individuals but with sizeable nations as a whole? Thus, those who were once Iberians, Tyrrhenians, and Sabines are called “Romans” [translation by John Barclay, Flavius Josephus, Against Apion, p. 190]; Berthelot, Philanthrôpia judaica, p. 37-43). The use of the word to enspondon, “treaty (of peace),” at the end of §107, where Philo writes that Egyptians should benefit from such a treaty, further suggests that Philo has the Roman model in mind (that is, the model described by Cicero, Livy or Tacitus, who referred to the Romans’ attitude toward their enemies at the time of the Republic).
The Romans, however, did not grant citizenship to Egyptians who were not already Greek citizens of one of the three poleis of Egypt, Alexandria, Naucratis and Ptolemais. Josephus, who claims that Apion was originally an Egyptian, emphasizes that “it is only to Egyptians that the Romans, who are now rulers of the world, have refused to grant any form of citizenship” (Against Apion II.41, translation by John Barclay, Flavius Josephus, Against Apion, p. 191). The question arises as to whether Philo, who shared the contempt and hostility of part of the Romans toward the Egyptians, used the example of Deuteronomy 23:8b-9 with an implicit a fortiori argument in mind: if the Jews were ready to go further than the Romans and grant citizenship even to Egyptians, then their philanthrōpia was greater than that of Rome.
In any case, this passage of On Virtues shows that Philo’s discourse on the integration of foreigners into the people of Israel (via conversion) was influenced by Roman and pro-Roman discourses about Roman citizenship.