Bava Kamma 38B

מואבים עצמן לא כל שכן?

with regard to the Moabites themselves, is it not clear all the more so that they should be attacked?

אמר לו הקדוש ברוך הוא: לא כשעלתה על דעתך עלתה על דעתי, שתי פרידות טובות יש לי להוציא מהן ⁠– רות המואביה ונעמה העמונית.

To counter this, God said to him: That which has entered your mind has not entered Mine, because I have two virtuous fledglings [feridot], i.e., girls, to extract from them: Ruth the Moabite, who will be the foremother of the dynasty of David, and Naamah the Ammonite, Solomon’s wife, from whom the continuation of that dynasty will emerge. For the sake of these women, the Moabites and Ammonites must not be destroyed.

והלא דברים קל וחומר, ומה בשביל שתי פרידות טובות ⁠– חס הקדוש ברוך הוא על שתי אומות גדולות ולא החריבן; בתו של רבי ⁠– אם כשרה היא וראויה היא לצאת ממנה דבר טוב, על אחת כמה וכמה דהוה חיה.

Ulla continued: And are these matters not inferred a fortiori? If for the sake of two virtuous fledglings God had pity on two large nations and did not destroy them, then if the daughter of my teacher! Rav Shmuel bar Yehuda, was righteous, and she had the potential for something good to emerge from her, it is all the more so clear that she would have lived.

אמר רבי חייא בר אבא אמר רבי יוחנן: אין הקדוש ברוך הוא מקפח שכר כל בריה, אפילו שכר שיחה נאה.

§ Having mentioned the Moabites and Ammonites, the Talmud cites that R' Ḥiyya bar Abba says that R' Yoḥanan says: God does not deprive any creature of its reward. He rewards every person for his good deeds, and provides reward even for using pleasant speech by using euphemisms.

דאילו בכירה דקאמרה ״מואב״, אמר לו הקדוש ברוך הוא למשה ״אל תצר את מואב ואל תתגר בם מלחמה״⁠ – מלחמה הוא דלא, הא אנגריא עביד בהו;

As with regard to the descendants of the elder of the two daughters of Lot, who said that the name of her son, whom she conceived with her father, would be Moab, meaning: From father, God said to Moses: “Do not be at enmity with Moab, neither contend with them in battle,” indicating that specifically a full-fledged battle was not authorized but that the Jewish people could impose forced labor [angarya] on them.