The burden of proof is upon the plaintiff, and the oath is upon the one who is accused.
Any accused is innocent until proven guilty
الْبَيِّنَةُ عَلَى الْمُدَّعِى وَالْيَمِينُ عَلَى الْمُدَّعَى عَلَيْهِ
The burden of proof is upon the plaintiff, and the oath is upon the one who is accused
(Tirmidhi)
لَوْ كُنْتُ رَاجِمًا أَحَدًا بِغَيْرِ بَيِّنَةٍ لَرَجَمْتُهَا
If I were going to stone anyone without proof, I would have stoned her
(Muslim)
Commentary
a. In the first narration, the Messenger of Allah صلى الله عليه وسلم explained that the proof should be provided by the person making the claim. If he has no proof but makes an accusation then the defendant can make an oath upon his position and in that manner the accusation is rejected by the Judge. This serves as evidence that the defendant is innocent until proven guilty.
b. In the second narration, the conjunction “لو” (if) in the Arabic language denotes abstention due to the absence of something, so in this case it means that the stoning was not carried out due to the absence of evidence.
c. This confirms that the Prophet صلى الله عليه وسلم did not stone the woman mentioned due to the absence of evidence even though there was strong suspicion of adultery.
d. In a narration ibn Abbas (ra) explains that the woman in question was someone who publicised evil after she had become Muslim. Imam ibn Hajr said the indication is that there was doubt upon her due to her environment and the people who used to visit her. Imam Nawawi mentioned that the meaning that she displayed evil is that she was known for it and that this was famous, however there was no clear evidence and neither did she confess (the evidence required to prove fornication is four direct witnesses or confession). Therefore the hadith is evidence that Hudood is not established by news even if it well known unless it is proven by Shari’ah evidence.
e. Therefore the ruler is forbidden from imposing a penalty on anyone, unless they perpetrate a crime which Shari’ah considers to be a crime, and the perpetration of the crime has been proven before a competent judge in a judiciary court, because the evidence could not be admissible unless it is established before a competent judge and in a judiciary court.