What is the condition regarding the accuser presenting evidence (bayyinah) for the implementation of the slander penalty?

Primary text

For the implementation of the hadd penalty following complete slander, it is required that the slanderer does not produce four witnesses (bayyinah). This is mandated by the Quranic injunction which requires flogging when the accusers fail to bring four witnesses. The penalty is also conditioned upon the absence of the accused's confession (iqrar), as confession is considered equivalent to the presentation of evidence.