If she is penetrated in the anus, it enters into the general meaning of the verse. As for intercourse with an animal, if we say that it mandates the hadd, it is not established except by four witnesses. If we say it does not mandate anything other than ta'zir (discretionary punishment), there are two perspectives regarding it: one is that it is established by two witnesses, because it does not mandate the hadd, so it is established by two witnesses like other civil rights. The second is that it is not established except by four. This is the opinion of the Qadi, because it is an indecency (fahisha) and because it is an act of penetration into a prohibited private part, so it resembles adultery. Following this analogy, every act of intercourse that does not mandate the hadd but mandates ta'zir, such as intercourse with a shared slave woman or one's own married slave woman—if it is not an act of intercourse, such as physical contact without the genitals and the like—it is established by two witnesses, unanimously, because it is not intercourse, so it resembles other rights.

Section: The Imam shall not perform the hadd based on his own knowledge. This has been narrated from Abu Bakr al-Siddiq, may Allah be pleased with him. Malik and the scholars of opinion (ashab al-ra'y) also held this view. It is one of the two opinions of Al-Shafi'i. He said in the other: He is permitted to perform it based on his own knowledge. This is the opinion of Abu Thawr; because if it is permissible for him to perform it based on evidence (bayyina) and confession—which only yield probability—then [acting] on what yields knowledge is more appropriate. Our evidence is the saying of Allah the Almighty: "Then bring against them four witnesses from among you." And He, the Almighty, said: "And when they do not bring the witnesses, then it is they who, in the sight of Allah, are the liars." And Umar said: "Or if there is pregnancy or confession." Also, because it is not permissible for him to speak of it, and if he were to accuse him based on what he knew of him, he would be a slanderer (qadhif), and the hadd of slander would be binding upon him; thus it is not permissible to perform the hadd based on it, like the statement of anyone else. Moreover, if it is forbidden to utter it, then acting upon it is even more forbidden. As for the master, if he knows of his slave or slave woman something that mandates the hadd upon them, may he perform it upon them? There are two perspectives: one is that he does not have the authority to perform it upon them, for the same reason we mentioned regarding the Imam. And because if the Imam does not possess the authority to perform it based on his own knowledge, despite the strength of his authority and the consensus on delegating the hadd to him, then others are even less entitled. The second perspective is that he possesses that right, because the master has the authority to discipline his slave based on his own knowledge, and this is treated in the same manner as discipline, and because the master has a more specific relationship with his slave, more complete authority over him, and is more compassionate than the Imam is toward the rest of the people.