James 5:12

But most of all, my brothers, do not take oaths, not by the heaven, or by the earth, or by any other thing: but let your Yes be Yes, and your No be No: so that you may not be judged.

Matthew 5:33-37

Again, you have knowledge that it was said in old times, Do not take false oaths, but give effect to your oaths to the Lord:

Matthew 23:16-22

A curse is on you, blind guides, who say, Whoever takes an oath by the Temple, it is nothing; but whoever takes an oath by the gold of the Temple, he is responsible.

1 Corinthians 11:34

If any man is in need of food, let him take his meal in his house; so that you may not come together to your damage. And the rest I will put in order when I come.

2 Corinthians 1:17-20

If then I had such a purpose, did I seem to be changing suddenly? or am I guided in my purposes by the flesh, saying, Yes, today, and, No, tomorrow?

James 3:1-2

Do not all be teachers, my brothers, because we teachers will be judged more hardly than others.

1 Peter 4:8

And most of all be warm in your love for one another; because in love there is forgiveness for sins without number:

3 John 1:2

My loved one, it is my prayer that you may do well in all things, and be healthy in body, even as your soul does well.

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
And most of all be warm in your love for one another; because in love there is forgiveness for sins without number:
3 John 1:2
My loved one, it is my prayer that you may do well in all things, and be healthy in body, even as your soul does well.

Swear not

Matthew 5:33
Again, you have knowledge that it was said in old times, Do not take false oaths, but give effect to your oaths to the Lord:
Matthew 23:16
A curse is on you, blind guides, who say, Whoever takes an oath by the Temple, it is nothing; but whoever takes an oath by the gold of the Temple, he is responsible.

But

2 Corinthians 1:17
If then I had such a purpose, did I seem to be changing suddenly? or am I guided in my purposes by the flesh, saying, Yes, today, and, No, tomorrow?

Lest

James 3:1
Do not all be teachers, my brothers, because we teachers will be judged more hardly than others.
1 Corinthians 11:34
If any man is in need of food, let him take his meal in his house; so that you may not come together to your damage. And the rest I will put in order when I come.

General references

Deuteronomy 5:11
You are not to make use of the name of the Lord your God for an evil purpose; whoever takes the Lord's name on his lips for an evil purpose will be judged as a sinner by the Lord.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain