[Machine] It is Dhuhr prayer. Indeed, the Messenger of Allah ﷺ used to pray Dhuhr at the time of Hajirah, while the people were in their homes. So, there would be no one behind him except for the rows of Saf and Safan. Then Allah Almighty revealed, "And observe the prayers and the middle prayer" [Al-Baqarah 2:238]. Amr ibn Abi Hakim opposed him.
هِيَ الظُّهْرُ إِنَّ رَسُولَ اللهِ ﷺ كَانَ يُصَلِّي الظُّهْرَ بِالْهَاجِرَةِ وَالنَّاسُ فِي قَائِلَتِهِمْ فَلَا يَكُونُ خَلْفَهُ إِلَّا الصَّفُّ وَالصَّفَّانِ فَأَنْزَلَ اللهُ تَعَالَى {حَافِظُوا عَلَى الصَّلَوَاتِ وَالصَّلَاةِ الْوُسْطَى} [البقرة 238] خَالَفَهُ عَمْرُو بْنُ أَبِي حَكِيمٍ