SHOULD WE SWEAR OATHS?

Numbers 30:2  If a man vow a vow unto the LORD, or swear an oath to bind his soul with a bond; he shall not break his word, he shall do according to all that proceedeth out of his mouth. (KJV) Matthew 5:34-35  But I say unto you, Swear not at all; neither by heaven; for it is God's throne: Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King. (KJV)

The Numbers passage is saying that, if we make an oath, we should keep it.  It is not telling us that we should make oaths (the same way that saying that you should apologize if you hurt someone doesn't mean that you should hurt someone).  Jesus, in Matthew 5, is speaking out against the frequent requiring and using of oaths, and is rather emphasizing simple honesty in all matters. Not a contradiction.