Tractate Shevuot - Chapter 3 - Mishnah 11

A vain oath applies to men and women, to relatives and non-relatives, to those qualified [to bear witness] and those not qualified, [whether uttered] before the court, or not before the court, [but it must be uttered] with a man's own mouth. And he is liable, for intentional transgression, stripes, and for unintentional transgression he is exempt. [In the case of] both this and that [oath], if he was adjured by the mouth of others, he is liable. How so? If he said, “I have not eaten today,” or, “I have not put on tefillin today” [and the another person said,] “I adjure thee,” and he said, “Amen!”, he is liable [if his oath was false].