Ubaydullah bin Abi Yazid asked Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) about "The fornicator does not marry except a fornicatress or a polytheist woman" [Surah al-Nur: 3]. He said: "This is a ruling between the two of them."
Imam al-Shafi'i (may Allah have mercy on him) says: It is narrated from Ikrimah (may Allah have mercy on him) that the fornicator commits zina only with a fornicatress or a polytheist woman, and none commits zina with the fornicatress except a fornicator or a polytheist man; he takes the word "marries" (yankihu) to mean "has intercourse".
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13865