God judges the Jews during the Day and the Gentiles at Night
א”ר לוי “והוא ישפט תבל בצדק ידין לאומים במישרים” (תהילים ט:ט) הקב”ה דן את ישראל ביום בשעה שהן עסוקין במצות (ואת האומות בלילה בשעה שהן בטילין מן העבירות (ראש השנה א:ג ז,א
In Sifre Devarim (#37) and in Tana De-be Eliyahu (#2) תבל refers to the Land of Israel. In Rabbi Levi’s teaching more likely, it refers to the occupants of the Land of Israel, the Jewish People.
בצדק is understood in a dual sense: “With righteousness” or “at the time of righteousness”. במישרים has similarly has the dual sense of “With evenness” or “at the time of evenness”. The terms are apparently nuanced. The former has the more positive sense of performing commandments while the latter has the more neutral sense of not committing sins.
God’s perception of the Jews in contrast to the Gentiles is here one of polar opposites and exceedingly negative towards the latter. Jews are basically good while gentiles are basically bad. Still, God judges not only Jews favorably, but also Gentiles over which He too reigns.
God is portrayed with human qualities as having an emotional disposition towards people. God’s judgement is not based solely on the principle of measure for measure, but is influenced by the person’s actions at the time of judgment.
Rel: Rosh Hashanah 16a