Romans 11:31

so they too have now become disobedient so that they too may one day receive mercy because of the mercy shown to you.

Romans 10:16

But they did not all pay attention to the good news [of salvation]; for Isaiah says, “Lord, who has believed our report?”

Romans 11:15

For if their [present] rejection [of salvation] is for the reconciliation of the world [to God], what will their acceptance [of salvation] be but [nothing less than] life from the dead?

Romans 11:25

I do not want you, believers, to be unaware of this mystery [God’s previously hidden plan]—so that you will not be wise in your own opinion—that a partial hardening has [temporarily] happened to Israel [to last] until the full number of the Gentiles has come in;

Treasury of Scripture Knowledge

Summary

Even so have these also now not believed, that through your mercy they also may obtain mercy.

General references

Bible References

Believed

Romans 10:16
But they did not all pay attention to the good news [of salvation]; for Isaiah says, “Lord, who has believed our report?”
Romans 11:15
For if their [present] rejection [of salvation] is for the reconciliation of the world [to God], what will their acceptance [of salvation] be but [nothing less than] life from the dead?

General references

Isaiah 55:9

“For as the heavens are higher than the earth,
So are My ways higher than your ways
And My thoughts higher than your thoughts.
Micah 7:20

You shall give truth to Jacob
And lovingkindness and mercy to Abraham,
As You have sworn to our forefathers
From the days of old.