Negative Commandment #30
Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
30. It is a negative commandment "Do not swear falsely concerning a money matter"
As it states in Vayikra (Leviticus) 19:11, "You shall not lie one man to another." A person that sues his friend for money that is worth an equivalent amount of a prutah or more (excluding land and deeds), if the person admits that he is required to pay it (excluding fines), but he denied it and swore, or the person that is suing the other one requires his friend to take an oath and his friend denies it, the friend is found guilty, even if he did not swear. This is called a Shevua HaPikadon, and he is required to pay the principal amount plus a penalty of a fifth of the principal. The person that transgresses this commandment also transgresses the commandment of "do not swear falsely in My Name." (19:12) This is a Shevua Betu'i. If a person denies a claim to land or deeds and swears falsely on this, he is not liable for a Shevua HaPikadon, but is for a Shevua Betu'i, because he swore falsely.
This applies in all places and at all times, for men and for women.