Hebrews 6:13
For when God made the promise to Abraham, because He could swear by no greater, He sware by Himself, saying,
Hebrews 3:18
and to whom did He swear that they should not enter into his rest, but to those that were disobedient?
Hebrews 6:17
Wherefore God being willing more abundantly to manifest unto the heirs of the promise the immutability of his counsel, confirmed it 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 should not enter into his rest, but to those that were disobedient?
Hebrews 6:13
For when God made the promise to Abraham, because He could swear by no greater, He sware by Himself, saying,