Hebrews 6:13

For God, when making a promise to Abraham, since He had no one greater by whom to swear, swore by Himself,

Luke 1:73

the oath which He swore to Abraham, our father;

Hebrews 6:16-18

For men swear by the greater; and the oath for confirmation is an end, to them, of every dispute:

Treasury of Scripture Knowledge

Summary

For when God made promise to Abraham, because he could swear by no greater, he sware by himself,

General references

Bible References

He sware

Hebrews 6:16
For men swear by the greater; and the oath for confirmation is an end, to them, of every dispute:
Luke 1:73
the oath which He swore to Abraham, our father;

General references

Revelation 10:6
and swore by Him Who liveth forever and ever, Who created the heaven and the things therein, and the earth and the things therein, and the sea and the things therein, that there shall be delay no longer;