James 5:12

But above all things, my brethren, swear not, neither by the heaven, nor by the earth, nor by any other oath: but let your yea be yea, and your nay, nay; that ye fall not under judgment.

Matthew 5:33-37

Again, ye have heard that it was said to them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:

Matthew 23:16-22

Woe unto you, ye blind guides, that say, Whosoever shall swear by the temple, it is nothing; but whosoever shall swear by the gold of the temple, he is a debtor.

1 Corinthians 11:34

If any man is hungry, let him eat at home; that your coming together be not unto judgment. And the rest will I set in order whensoever I come.

2 Corinthians 1:17-20

When I therefore was thus minded, did I show fickleness? or the things that I purpose, do I purpose according to the flesh, that with me there should be the yea yea and the nay nay?

James 3:1-2

Be not many of you teachers, my brethren, knowing that we shall receive heavier judgment.

1 Peter 4:8

above all things being fervent in your love among yourselves; for love covereth a multitude of sins:

3 John 1:2

Beloved, I pray that in all things thou mayest prosper and be in health, even as thy soul prospereth.

Treasury of Scripture Knowledge

Summary

But above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea; and your nay, nay; lest ye fall into condemnation.

General references

Bible References

Above

1 Peter 4:8
above all things being fervent in your love among yourselves; for love covereth a multitude of sins:
3 John 1:2
Beloved, I pray that in all things thou mayest prosper and be in health, even as thy soul prospereth.

Swear not

Matthew 5:33
Again, ye have heard that it was said to them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:
Matthew 23:16
Woe unto you, ye blind guides, that say, Whosoever shall swear by the temple, it is nothing; but whosoever shall swear by the gold of the temple, he is a debtor.

But

2 Corinthians 1:17
When I therefore was thus minded, did I show fickleness? or the things that I purpose, do I purpose according to the flesh, that with me there should be the yea yea and the nay nay?

Lest

James 3:1
Be not many of you teachers, my brethren, knowing that we shall receive heavier judgment.
1 Corinthians 11:34
If any man is hungry, let him eat at home; that your coming together be not unto judgment. And the rest will I set in order whensoever I come.

General references

Deuteronomy 5:11
Thou shalt not take the name of Jehovah thy God in vain: for Jehovah will not hold him guiltless that taketh his name in vain.

American Standard Version Public Domain