Romans 4:16-18

therefore the inheritance is of faith, that it might be meerly of favour, to the end the promise might be assured to all his posterity, not to that part only who have the law, but to that also who have the faith of Abraham, the father of us all, as it is written,

Hebrews 11:12

so that even a single person whose vigour was gone, gave rise to a posterity as numerous as the stars of the sky, or the sands on the sea-shore, which cannot be numbred.

Revelation 7:9

After this I beheld, and there was a great multitude, which no man could number, of every nation, tribe, people, and language, who stood before the throne, and before the lamb cloathed in white robes, having palms 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
therefore the inheritance is of faith, that it might be meerly of favour, to the end the promise might be assured to all his posterity, not to that part only who have the law, but to that also who have the faith of Abraham, the father of us all, as it is written,
Hebrews 11:12
so that even a single person whose vigour was gone, gave rise to a posterity as numerous as the stars of the sky, or the sands on the sea-shore, which cannot be numbred.
Revelation 7:9
After this I beheld, and there was a great multitude, which no man could number, of every nation, tribe, people, and language, who stood before the throne, and before the lamb cloathed in white robes, having palms in their hands.