Romans 9:7

neither are they who are the race of Abraham, all children: but 'tis said, "in Isaac shall thy posterity be called."

Hebrews 11:18

of whom it was said, "only the descendants of Isaac shall be counted your posterity:"

Luke 3:8

let your actions therefore show your repentance, and don't pretend to say within yourselves, "we have Abraham for our father:" for I tell you that God is able of these stones to raise up children to Abraham.

Luke 16:24-25

and he cry'd out, saying, father Abraham, take pity on me, and send Lazarus to dip the tip of his finger in water to cool my tongue; for I am tormented in this flame.

Luke 16:30

no, father Abraham, said he, they will not: but if any of the dead went to them, they will certainly repent.

John 8:33

they answered him, we are Abraham's offspring, and were never slaves to any man: why then do you say, "ye shall be made free?"

John 8:37-39

I know you are Abraham's offspring; but ye seek to kill me, because my doctrine doth not penetrate into you.

Galatians 4:23

he, who was of the bond-woman, was born according to the ordinary course of nature; but he, who was of the free-woman, was born by virtue of the promise.

Philippians 3:3

for we are the genuine sons of Abraham, who worship God in the spiritual manner, and value no other dependance than that on Jesus Christ, without confiding in any external advantages:

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 actions therefore show your repentance, and don't pretend to say within yourselves, "we have Abraham for our father:" for I tell you that God is able of these stones to raise up children to Abraham.
Luke 16:24
and he cry'd out, saying, father Abraham, take pity on me, and send Lazarus to dip the tip of his finger in water to cool my tongue; for I am tormented in this flame.
John 8:37
I know you are Abraham's offspring; but ye seek to kill me, because my doctrine doth not penetrate into you.
Philippians 3:3
for we are the genuine sons of Abraham, who worship God in the spiritual manner, and value no other dependance than that on Jesus Christ, without confiding in any external advantages:

In isaac

Hebrews 11:18
of whom it was said, "only the descendants of Isaac shall be counted your posterity:"