1 Corinthians 14:11

If then I do not know the meaning of the language, I will be to the one who speaks a barbarian, and the one who speaks will be a barbarian to me.

Acts 28:2

The natives showed us extraordinary kindness; for because of the rain that had set in and because of the cold, they kindled a fire and received us all.

Acts 28:4

When the natives saw the creature hanging from his hand, they began saying to one another, “Undoubtedly this man is a murderer, and though he has been saved from the sea, justice has not allowed him to live.”

Romans 1:14

I am under obligation both to Greeks and to barbarians, both to the wise and to the foolish.

1 Corinthians 14:21

In the Law it is written, “By men of strange tongues and by the lips of strangers I will speak to this people, and even so they will not listen to Me,” says the Lord.

Colossians 3:11

a renewal in which there is no distinction between Greek and Jew, circumcised and uncircumcised, barbarian, Scythian, slave and freeman, but Christ is all, and in all.

Treasury of Scripture Knowledge

Summary

Therefore if I know not the meaning of the voice, I shall be unto him that speaketh a barbarian, and he that speaketh shall be a barbarian unto me.

Bible References

I shall

1 Corinthians 14:21
In the Law it is written, “By men of strange tongues and by the lips of strangers I will speak to this people, and even so they will not listen to Me,” says the Lord.
Acts 28:2
The natives showed us extraordinary kindness; for because of the rain that had set in and because of the cold, they kindled a fire and received us all.
Romans 1:14
I am under obligation both to Greeks and to barbarians, both to the wise and to the foolish.
Colossians 3:11
a renewal in which there is no distinction between Greek and Jew, circumcised and uncircumcised, barbarian, Scythian, slave and freeman, but Christ is all, and in all.