James 5:12

Again, above all things, my brothers, swear not at all, neither by the heavens, nor by the earth, nor by any other oath. Let your "yes" be "yes," and your "no," "no," so you will not fall under condemnation.

Matthew 5:33-34

"Again you have heard that it was said to the men of old, "You must not forswear yourselves, but must perform your vows to the Lord.

Treasury of Scripture Knowledge

Summary

And ye shall not swear by my name falsely, neither shalt thou profane the name of thy God: I am the LORD.

Bible References

Ye shall

Matthew 5:33
"Again you have heard that it was said to the men of old, "You must not forswear yourselves, but must perform your vows to the Lord.
James 5:12
Again, above all things, my brothers, swear not at all, neither by the heavens, nor by the earth, nor by any other oath. Let your "yes" be "yes," and your "no," "no," so you will not fall under condemnation.