Romans 9:7

Nor, because they are Abraham's descendants, are they all his Children; but-'It is Isaac's children who will be called thy descendants.'

Hebrews 11:18

of whom it had been said-- 'It is through Isaac that there shall be descendants to bear thy name.'

Luke 3:8

Let your lives, then, prove your repentance; and do not begin to say among yourselves 'Abraham is our ancestor,' for I tell you that out of these very stones God is able to raise descendants for Abraham!

Luke 16:24-25

So he called out 'Pity me, Father Abraham, and send Lazarus to dip the tip of his finger in water and cool my tongue, for I am suffering agony in this flame.'

Luke 16:30

'But, Father Abraham,' he urged, 'if some one from the dead were to go to them, they would repent.'

John 8:33

"We are descendants of Abraham," was their answer, "and have never yet been in slavery to any one. What do you mean by saying 'you will be set free'?"

John 8:37-39

I know that you are descendants of Abraham; yet you are seeking to put me to death, because my Message finds no place in your hearts.

Galatians 4:23

But the child of the slave-woman was born in the course of nature, while the child of the free woman was born in fulfillment of a promise.

Philippians 3:3

For it is we who are the circumcised--we whose worship is prompted by the Spirit of God, who exult in Christ Jesus, and who do not rely upon external privileges;

Treasury of Scripture Knowledge

Summary

Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.

In isaac

Bible References

Because

Luke 3:8
Let your lives, then, prove your repentance; and do not begin to say among yourselves 'Abraham is our ancestor,' for I tell you that out of these very stones God is able to raise descendants for Abraham!
Luke 16:24
So he called out 'Pity me, Father Abraham, and send Lazarus to dip the tip of his finger in water and cool my tongue, for I am suffering agony in this flame.'
John 8:37
I know that you are descendants of Abraham; yet you are seeking to put me to death, because my Message finds no place in your hearts.
Philippians 3:3
For it is we who are the circumcised--we whose worship is prompted by the Spirit of God, who exult in Christ Jesus, and who do not rely upon external privileges;

In isaac

Hebrews 11:18
of whom it had been said-- 'It is through Isaac that there shall be descendants to bear thy name.'