Romans 11:10
Let their eyes become [spiritually] dim so they cannot see, and may their backs always bend [i.e., under heavy burdens]."
Matthew 13:14-15
So, the prophecy of Isaiah is being fulfilled by them, which says, [Isa. 6:9f] 'You will hear all right, but you will not understand [what you hear]. You will see all right but you will not perceive [what you see].
John 12:39-40
They were not able to believe because Isaiah also said [Isa. 6:10],
Acts 28:26-27
saying, [Isa. 6:9-10], 'Go to these people and say, you will hear all right, but you will not understand [what you hear]. You will see all right, but you will not perceive [what you see].
Romans 11:25
For I want you to know this secret, brothers, so you will not become conceited: Part of the Israelites have become [spiritually] insensitive [to God], [and will remain that way] until the fullness of the Gentiles occurs. [Note: As with verse 12, concerning the Jews, "fullness" here may mean either a large or the complete number of Gentiles who will be saved].
2 Corinthians 3:14
But the minds of the Israelites became dull for, to this very day, the same veil remains on them [i.e., figuratively] when the Old Agreement [Scriptures] are read. It is not being revealed to them that the Old Agreement is being abolished by Christ [i.e., by His death on the cross. See Col. 2:14].