Luke 1:72-73

to show mercy to our forefathers, and carry out His sacred covenant,

Acts 3:25

And you are the descendants of the prophets and the heirs of the sacred compact which God made with your forefathers, when He said to Abraham: 'All the families of the earth are to be blessed through your posterity.'

Galatians 3:15-17

Brothers, I am going to use a human illustration: Even a human contract, once it has been ratified, no one can annul or change.

Hebrews 6:13-18

For when God made His promise to Abraham, He took an oath by Himself, since He had no one greater by whom He could take it,

Treasury of Scripture Knowledge

Summary

Even of the covenant which he made with Abraham, and of his oath unto Isaac;

Bible References

Which he made

Luke 1:72
to show mercy to our forefathers, and carry out His sacred covenant,
Acts 3:25
And you are the descendants of the prophets and the heirs of the sacred compact which God made with your forefathers, when He said to Abraham: 'All the families of the earth are to be blessed through your posterity.'
Galatians 3:15
Brothers, I am going to use a human illustration: Even a human contract, once it has been ratified, no one can annul or change.
Hebrews 6:13
For when God made His promise to Abraham, He took an oath by Himself, since He had no one greater by whom He could take it,