Genesis 21:24

And Abraham said, I, will swear.

Genesis 14:13

Then came in a fugitive, and told Abram the Hebrew, - he, having his dwelling among the oaks of Mature the Amorite brother of Eshcol and brother of Aner, they, also having a covenant with Abram.

Romans 12:18

If possible - so far as dependeth on you, with all men being at peace:

Hebrews 6:16

For, men, by the greater one, swear, and, with them, an end of all gainsaying by way of confirmation is, the oath:

Treasury of Scripture Knowledge

Summary

And Abraham said, I will swear.

Bible References

General references

Genesis 14:13
Then came in a fugitive, and told Abram the Hebrew, - he, having his dwelling among the oaks of Mature the Amorite brother of Eshcol and brother of Aner, they, also having a covenant with Abram.
Romans 12:18
If possible - so far as dependeth on you, with all men being at peace:
Hebrews 6:16
For, men, by the greater one, swear, and, with them, an end of all gainsaying by way of confirmation is, the oath: