Sahih al-Bukhari 4489
Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · Narrated by Anas
Arabic
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا مُعْتَمِرٌ، عَنْ أَبِيهِ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ لَمْ يَبْقَ مِمَّنْ صَلَّى الْقِبْلَتَيْنِ غَيْرِي.
English translation
Narrated Anas:None remains of those who prayed facing both Qiblas (that is, Jerusalem and Mecca) except myself
Reference: Sahih al-Bukhari 4489, Book of Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)). English translation by Dr. Muhammad Muhsin Khan.