Romans 11:11-12, 17, 23-24

So I say, have they stumbled so as to fall [to spiritual ruin]? Certainly not! But by their transgression [their rejection of the Messiah] salvation has come to the Gentiles, to make Israel jealous [when they realize what they have forfeited]. Now if Israel’s transgression means riches for the world [at large] and their failure means riches for the Gentiles, how much more will their fulfillment and reinstatement be!

But if some of the branches were broken off, and you [Gentiles], being like a wild olive shoot, were grafted in among them to share with them the rich root of the olive tree

And even they [the unbelieving Jews], if they do not continue in their unbelief, will be grafted in; for God has the power to graft them in again. For if you were cut off from what is by nature a wild olive tree, and against nature were grafted into a cultivated olive tree, how much easier will it be to graft these who are the natural branches back into [the original parent stock of] their own olive tree?