"I do not want you to be ignorant of this mystery, brothers, so that you will not be conceited: A hardening in part has come to Israel, until the full number of the Gentiles has come in. Rom 11:25

But then, at the seventh trumpet, when the full number of Gentiles has come in, something changes...

“There will be no more delay! But in the days when the seventh angel is about to sound his trumpet, the mystery of God will be accomplished, just as He announced to His servants the prophets.” Rev 10:7

And what did He announce to His servants the prophets...

"I will restore Jacob from captivity and will have compassion on the whole house of Israel, and I will be jealous for My holy name... I will show My holiness in them in the sight of many nations. Then they will know that I am the LORD their God... And I will no longer hide My face from them, for I will pour out My Spirit on the house of Israel, declares the Lord GOD." Ezek 39:25-29