Or HaChaim on Deuteronomy 32:43/אור החיים על דברים ל״ב:מ״ג

1 הרנינו גוים עמו, "O nations, sing the praises of His people, etc." Moses means that when the time comes that G'd exacts retribution from the nations, from the enemies of the Jewish people, the other nations will praise the Israelites and jubilate and elevate them, as we know from Psalms 144,19: "Hail to the people who experience this."

2כי דם עבדיו יקום, "for He will avenge the blood of His servants." The verse tells us that G'd will not only avenge the blood Israel's enemies have shed but also the other afflictions they have caused the Jewish people. G'd will even avenge evil intentions against the Jewish people which have not been carried out as indicated in Psalms 7,17: ישוב עמלו בראשו, "His mischief will recoil upon his own head." [The Psalmist had previously spoken about people who dug a pit intended for a third party to fall into (verse 16). Ed.]

3וכפר אדמתו עמו, "Any residual sins of His people, its land will atone for." The desolation of ארץ ישראל for many many years was part of the atonement process for its people.