Sahih al-Bukhari, Hadith 7093 ⓘ
Narrated Ibn `Umar: I heard Allah's Messenger while he was facing the East, saying, "Verily! Afflictions are there, from where the side of the head of Satan comes out."
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم وَهْوَ مُسْتَقْبِلٌ الْمَشْرِقَ يَقُولُ " أَلاَ إِنَّ الْفِتْنَةَ هَا هُنَا مِنْ حَيْثُ يَطْلُعُ قَرْنُ الشَّيْطَانِ " .
also referenced under: Book 92, Hadith 44 (In-Book) & Volume 9, Book 88, Hadith 213 (USC-MSA)