Since
the punishment for violating a Biblical oath is very severe, Rashi
writes that Jewish courts in his time refrained from asking the
defendant to swear and instead placed a curse on any defendant who would
lie.
If the defendant says, “I will not swear,” he is immediately excused
from court, owes money, and does not come back to change his opinion.
However, if he says, “I shall swear,” those standing there recite the
phrase “Turn away from the tents of these wicked men.” Even the
plaintiff is considered guilty for causing an oath, since he should not
have dealt with an untrustworthy person.
The judges tell him, “You should know that the whole world trembled at
the words 'Do not take the name of Hashem your God in vain'” And why is
this? Because about a false oath it says, “God will not absolve.”
Art: H. de la Charlerie - King Louis XVI Swearing on the Book of the Constitution