Even in the case of homicide when there are two witnesses...
Even in the case of homicide when there are two witnesses, the crime is proved, but in the question of accusation to adultery four witnesses are especially necessary. The reason that witness outweighs here is possibly the fact that many people accuse others very easily and they always mar reputation and honour of individuals suspiciously or not suspiciously. Islam is rather uncompromising in this respect so that people's honour can be saved.
But in other issues, even homicide, individuals' tongue is not so defiled. Moreover, in homicide there is only one party, i.e. the criminal is one, but in adultery two persons are charged with the crime, and if we require two witnesses for each of them, there will be four witnesses. This statement is the content of a tradition narrated from Imam Sadiq (a.s.). Abi Hanifah, the famous Sunni jurist, says: "I asked Imam Sadiq (a.s.) that whether fornication is more condemnable than homicide.
He said: 'No, homicide is.' Then I said: 'Why are two witnesses enough in proving homicide, but fornication requires 4 witnesses?' He said: 'What do you say about this matter?" Abi Hanifah could not answer explicitly. Imam said: "This is because there are two prescribed punishments in fornication, one of them is for man and the other one is for woman. So two witnesses are needed.
But in homicide only one prescribed punishment is inflicted on murderer."[^1] Of course there are some cases of fornication for which prescribed punishment is inflicted on one party (e.g. rape and suchlike), but these are the exceptional instances. What is common and obvious is the one that is committed with mutual agreement, but we know that the philosophy of ordinances depends on prevailing individuals. 3.
If he has really marred reputation and honour of a pure man or woman, he must, in order to make his repentance accepted, deny what he has said in the presence of those who have heard his accusation, so to speak, he must rehabilitate the disgraced person. The Qur'anic holy phrase /wa 'aslahu/ ("...who ... make amends ...") that has come after the phrase /tabu/ ("...