James 5:12

But above all things, my brethren, swear not; neither by 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 condemnation.

Matthew 5:33-37

Again ye have heard that it was said to them of old time, "Thou shalt not swear falsely, but shalt perform to the Lord thine oaths."

Matthew 23:16-22

Woe to you, blind guides, that say, Whoever sweareth by the temple, it is nothing; but whoever sweareth by the gold of the temple, is bound.

1 Corinthians 11:34

If any one hunger, let him eat at home; that ye may not come together to condemnation. And the rest I will set in order when I come.

2 Corinthians 1:17-20

Having, then, this purpose, did I act with levity? Or in my purposes do I resolve according to the flesh, that with me there should be now yea, yea, and now nay, nay?

James 3:1-2

My brethren, be not many teachers, knowing that we shall receive the greater condemnation.

1 Peter 4:8

And above all things have fervent love among yourselves; for love covereth a multitude of sins.

3 John 1:2

Beloved, in all things I pray that thou mayst prosper and be in health, 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.

Bible References

Above

1 Peter 4:8
And above all things have fervent love among yourselves; for love covereth a multitude of sins.
3 John 1:2
Beloved, in all things I pray that thou mayst prosper and be in health, 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 swear falsely, but shalt perform to the Lord thine oaths."
Matthew 23:16
Woe to you, blind guides, that say, Whoever sweareth by the temple, it is nothing; but whoever sweareth by the gold of the temple, is bound.

But

2 Corinthians 1:17
Having, then, this purpose, did I act with levity? Or in my purposes do I resolve according to the flesh, that with me there should be now yea, yea, and now nay, nay?

Lest

James 3:1
My brethren, be not many teachers, knowing that we shall receive the greater condemnation.
1 Corinthians 11:34
If any one hunger, let him eat at home; that ye may not come together to condemnation. And the rest I will set in order when I come.