Read: Matthew 5:33-37
Let what you say be simply "Yes" or "No"; anything more than this comes from evil. (Matthew 5:37 ESV)
"I swear" used to be a regularly heard phrase. Probably because of the popularity of a hit song by the same name. It spoke of the depth of the love a man had for a woman, and how he was swearing an oath based on all of these wondrous astrological things. It's a beautiful thought, but its deceptive.
Jesus taught his followers that their words were empty when there were too many of them. People did not need to accompany all of their promises to God, or each other, with all of the wordy oaths that had become so commonplace. "Yes" or "No" was enough.
I can readily identify with this idea. It's so easy to want to make grand proclamations in accompaniment with our promises. Still, its easy to want to make our promises more about the fact that we are making them in the first place, and less about what we are actually committing ourselves to do.
How many weddings have you been to that were absolutely breathtaking ceremonies either aesthetically or ritually? How many of them ended in disaster? None I hope, but the evidence is all around us. Hundreds and thousands of wonderfully worded weddings end abruptly every year. Forgotten are the word-filled vows to love and cherish until departure by death. What if the commitment to being together, the "Yes" was more important than the way it's displayed for the world?
Weddings are an easy to spot example, but this principle carries over into every day life. When someone asks us to pray for their need, we don't need to just quote them a scripture and agree to remember them later in prayer. We need to pray for them. Regularly. Right on the spot if possible. And there are many more examples we could discuss. The simple idea is that when you make an oath, when you promise, when you vow—"Yes" or "No" is enough.