Let your yes be yes

Matthew 5:33-48 (ESV)
"Again you have heard that it was said to those of old, 'You shall not swear falsely, but shall perform to the Lord what you have sworn.' [34] But I say to you, Do not take an oath at all, either by heaven, for it is the throne of God, [35] or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. [36] And do not take an oath by your head, for you cannot make one hair white or black. [37] Let what you say be simply 'Yes' or 'No'; anything more than this comes from evil.
Let your yes be yes! Let your no be no. It’s funny, you always hear people tell you, you shouldn’t swear. At least you do when you have my mouth. I rarely swear. I hear people swearing all the time. No one chastises them, they don’t even think about it. They tell me not to curse. I can’t remember the last time I did. I hear others do it, but it doesn’t phase anyone. But it all stems from those signs hanging up in youth halls that say “No cussing, cursing or swearing.” And everyone seems to have come to the conclusion that all three of those things are the same thing and have to do with scatological language, that is cussing. And somehow in all of this, the use of scatological language offends people more than OMG. In my mind there is just something extremely problematic about that.
In western morality, the prohibition against swearing comes from this passage among a few others. Swearing is the same as promising or taking an oath, and it is unbecoming of the Christian. In fact it should be offensive to a man to have his yes questioned at all, or his no. Why should you have to seal anything with an oath? Who is this other person who want s you to promise, or confirm what you said with an oath? Jesus identifies him. Now this isn’t all the Bible has to say about oath taking, but it should make one pause enough to realize that perhaps he shouldn’t be “swearing to God” over the latest peace of Gossip. At one time that sort of behavior was prosecutable, and came with jail time.