Again, you have heard that it was said to the first ones, “You shall not swear falsely, but you shall perform your oaths to HaShem. But I say to you, you shall not swear any oath—not by the heavens, for they are the throne of God, nor by the earth, for it is his footstool, nor by Yerushalayim, for it is the city of the great King. Not even by the life of your head shall you swear, since you are unable to turn one hair black or white. Instead, let your words be hen hen, lo lo, and anything beyond this is from the evil one. --Matthew 5:33-37, DHE
A later rabbinic discussion on the book of Ruth reflects this same perspective:
Then said she: Sit still my daughter . . . for the man will not rest until he have finished the thing (Ruth ). R. Huna said in the name of R. Samuel b. Isaac: The yes of the righteous is yes, and their no, no, as it is said, For the man will not rest until he have finished the thing this day.
Thus, the rabbinic sources, which allow for oath-taking and regulate its use in great detail, seem to hold the simple answer of “yes” or “no” as the ideal. Oath-taking may be part of life in this age, but it is not the ideal revealed in the earliest chapters of Scripture.
Yaakov, the brother of Yeshua, pictures this ideal toward the end of his letter: “Above all, my beloved, do not swear, either by heaven or by earth or by any other oath, but let your ‘Yes’ be yes and your ‘No’ be no, so that you may not fall under condemnation” (James. 5:12). It is significant that Yaakov’s prohibition of swearing comes not long after his extended treatment of the tongue, “a small member” that “boasts of great exploits” (ibid 3:5). Yaakov describes the tongue as a sort of bridle that controls the whole person: “Anyone who makes no mistakes in speaking is perfect, able to keep the whole body in check with a bridle” (ibid 3:2). Apparently avoiding mistakes in speaking includes avoiding oaths, which can lead to condemnation because they are readily broken. If one’s word is unreliable it cannot be propped up by taking an oath. As in the Roger Clemens interview, if I am not sure you are an inherently honest person, I’ll ask you to take an oath. But, of course, one who is not inherently honest might well violate the oath.
Oath-taking is not such a common practice today, but its lessons are clear: Truth is foundational to ethical behavior. Oath-taking, which is intended as a guardian of truthfulness, ends up weakening it. Instead of taking an oath to demonstrate his reliability, the follower of Yeshua simply speaks the truth.
Adapted from Divine Reversal: The Transforming Ethics of Jesus, by Rabbi Russell Resnik. Available at www.MessianicJewish.net or Amazon.com.