Thought from Today's Old Testament Passage:
Or if a soul swear, pronouncing with his lips to do evil, or to do good, whatsoever it be that a man shall pronounce with an oath, and it be hid from him; when he knoweth of it, then he shall be guilty in one of these [Lev. 5:4].
Careless speech is involved in this instance. Sometimes we promise to do something, and then we don't do it. We promise that we will serve the Lord. Jephthah is an example of a man promising to do something very rash—to offer his daughter. Simon Peter boldly declared that he would not deny Christ, but would die defending Him.
Today I hear people making some very rash promises. In fact, I think some of our songs are dynamite, to tell the truth. In our songs we promise to give all to Him, to follow Him, to die for Him. We sing them so glibly that we don't even know what we are singing.
Also I think it is careless speech and presumptuous when we try to demand of God an answer to our prayers. We need always to remember that our prayers are to be in accordance with His will. If we ask anything according to His will, He hears us. Where did we get the idea that we could demand anything of God?
J. Vernon McGee, Thru the Bible Commentary [computer file] electronic ed., Logos Library System (Nashville: Thomas Nelson) 1997, © 1981 by J. Vernon McGee