Romans 11:5, 16, 26

So too then, at the present time there has come to be a remnant [a small believing minority] according to God’s gracious choice.

If the first portion [of dough offered as the first fruits] is holy, so is the whole batch; and if the root (Abraham, the patriarchs) is holy, so are the branches (the Israelites). [Num 15:19-21]

and so [at that time] all Israel [that is, all Jews who have a personal faith in Jesus as Messiah] will be saved; just as it is written [in Scripture], “THE DELIVERER (Messiah) WILL COME FROM ZION, HE WILL REMOVE UNGODLINESS FROM JACOB.” [Is 59:20, 21]