Hadith 1144
الزاني بحليلة جاره لا ينظر الله اليه يوم القيامة ولا يزكيه ويقول له : ادخل النار مع الداخلين
"Allah Almighty will not look with mercy on the Day of Resurrection at the one who commits adultery with his neighbor's wife, nor will He purify him, and He will say to him, 'Enter along with those who are entering Hell.'"