Matthew 5:33-37
"Again, you have heard what was said to people in time's past [Lev. 19:12], 'You must not go back on your oaths, but [rather] fulfill the oaths you take to the Lord.'
Matthew 23:16-22
"It is too bad for you blind leaders who say that whoever takes an oath 'by the Temple,' it does not [really] mean anything, but whoever takes an oath 'by the gold of the Temple,' he is obligated to [fulfill] the oath.
James 5:12
But above everything else, my brothers, do not take oaths, not "by the heaven," nor "by the earth," nor by any other oath. But your "yes" should be [simply] "yes," and your "no," [simply] "no," so you do not fall under condemnation.