James 5:12
But above all things, my brothers, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yes be yes; and your no, no; lest you fall into condemnation.
Topicalbible.org—AKJV

Matthew 5:33-37
Again, you have heard that it has been said by them of old time, You shall not forswear yourself, but shall perform to the Lord your oaths:
Topicalbible.org—AKJV