Romans 4:16-18

This is why righteousness is of faith, that it may be a free gift; so that the promise stands firm to all Abraham's posterity; not to his children of his faith. For in the sight of the God in whom he believed, who gives life to the dead, and calls into being that which is not, Abraham is the father of us all both Jews and Gentiles,

Hebrews 11:12

and thus there sprang from one man, and him practically dead, a nation like the stars in the heavens in multitude, or grains of sand upon the seashore, innumerable.

Revelation 7:9

After this I looked, and behold a great multitude, whom no man could number, out of every nation and tribe and people and tongue, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands;

Treasury of Scripture Knowledge

Summary

And I will make thy seed as the dust of the earth: so that if a man can number the dust of the earth, then shall thy seed also be numbered.

Bible References

General references

Romans 4:16
This is why righteousness is of faith, that it may be a free gift; so that the promise stands firm to all Abraham's posterity; not to his children of his faith. For in the sight of the God in whom he believed, who gives life to the dead, and calls into being that which is not, Abraham is the father of us all both Jews and Gentiles,
Hebrews 11:12
and thus there sprang from one man, and him practically dead, a nation like the stars in the heavens in multitude, or grains of sand upon the seashore, innumerable.
Revelation 7:9
After this I looked, and behold a great multitude, whom no man could number, out of every nation and tribe and people and tongue, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands;