(1)  The oath shall only be taken on the application of the opposing party.

(2)  It shall be permissible for the judge, of his own motion, to direct that a party take the oath in the following circumstances:

(a)  if he claims a right in an inheritance and establishes the same, he shall take the oath of istithaq to show that he has not received what is due to him from the deceased, and that he has not discharged him, that he has not assigned his rights to another, and that there is no pledge in existence as against such right;

(b)  in the event of proof of his entitlement to property, he shall take the oath to show that he has not sold such property or that he has not given it as a gift, or that it has not left his possession by any other means;

(c)  in the event that a sale is rescinded for a defect, he must swear that he did not consent to the defect either by word or deed; or

(d)  in the event of a judgment for a right of pre-emption, he must take the oath to show that his right of pre-emption has not lapsed for any reason.