What are the conditions for Mubahala?

Mubahalah is when disputing parties concerning a matter gather and invoke Allah's curse upon whichever of them is the wrongdoer. It is legislated to establish the truth and to compel the obstinate with proof, based on the Almighty's saying: (Then whoever disputes with you concerning him [Jesus] after knowledge has come to you, say, "Come, let us call our sons and your sons and our women and your women and ourselves and yourselves, then let us invoke [Allah's curse] upon the liars.") Mubahalah is not exclusive to the Messenger, peace and blessings be upon him, but rather it is general, applying to him and his Ummah. Conditions for Mubahalah include sincere intention for Allah, that it be performed after establishing proof against the opponent, after their insistence on falsehood and their obstinacy against the truth has become clear, and that it be concerning an important matter of religion. It is not permissible in matters of ijtihad (independent reasoning), and it should only be resorted to out of necessity and after exhausting all means of removing doubts and offering advice.