Matthew 5:37
But let your ‘Yes’ be ‘Yes’ and your ‘No’ be ‘No.’ Whatever is more than these is of the evil one.
World English Bible (Public Domain)
In context
Before · Matthew 5:35–36
35nor by the earth, for it is the footstool of his feet; nor by Jerusalem, for it is the city of the great King. 36Neither shall you swear by your head, for you can’t make one hair white or black.
37But let your ‘Yes’ be ‘Yes’ and your ‘No’ be ‘No.’ Whatever is more than these is of the evil one.