The context makes it clear that the return of the Jewish people is evidence that God has forgiven their sins. This is echoed through the prophet Ezekiel.
You have forgiven the iniquity of Your people; You have covered all their sin. Selah
You have taken away all Your wrath; You have turned from the fierceness of Your anger.
Ezekiel 36: 24-26
For I will take you from among the nations, gather you out of all countries, and bring you into your own land. Then I will sprinkle clean water on you, and you shall be clean; I will cleanse you from all your filthiness and from all your idols. I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh.
PROCLAIM GOD’S PROMISE THAT HE WILL CLEANSE THE JEWISH PEOPLE FROM THEIR SINS AND RETURN THEM TO THE LAND.