Hebrews 6:13
For when God made a promise to Abraham, since he had no one greater by whom to swear, he swore by himself,
Hebrews 3:18
And to whom did he swear that they would never enter his rest, but to those who were disobedient?
Hebrews 6:17
So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he interposed with an oath,
Treasury of Scripture Knowledge
Summary
But if ye will not hear these words, I swear by myself, saith the LORD, that this house shall become a desolation.
Bible References
I
Hebrews 3:18
And to whom did he swear that they would never enter his rest, but to those who were disobedient?
Hebrews 6:13
For when God made a promise to Abraham, since he had no one greater by whom to swear, he swore by himself,