Hadithcore
Mishkat al-Masabih, 3194

He reported God’s Messenger as saying, “God will not look at him who has intercourse with his wife through her anus.” It is transmitted in <i>Sharh as-sunna</i>.

وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ الَّذِي يَأْتِي امْرَأَتَهُ فِي دُبُرِهَا لَا يَنْظُرُ اللَّهُ إِلَيْهِ» . رَوَاهُ فِي شرح السّنة

References1 variant
In-Book Reference
Book 13, Hadith 112