The Prophet ﷺ was standing at the door of Ayesha when he gestured with his hand toward the east and said, "Tribulation is here, where the horn of Satan rises."
حدثنا يحيى عن عبيد الله أخبرني نافع
عن النبي ﷺ أنه كان قائما عند باب عائشة فأشار بيده نحو المشرق فقال الفتنة هاهنا حيث يطلع قرن الشيطان
Its isnad is sahih. Muslim also reported it (2:367-368) through Yahya Qattan from Ubaydullah, and he reported it as well through other routes from Ibn Umar. Bukhari reported it (9:385 and 13:38) through several routes from Ibn Umar. Tirmidhi reported it (3:247) through Zuhri from Salim from his father, and said, "A hasan sahih hadith."