O people of the masjid! I have just come from the Prophet's ﷺ Masjid, and I prayed with him Zuhr, and he was praying facing Makkah! The command has come to change direction!
~the day of the Change of the Qibla (2 AH) · 2 AH
Details differ across the sources
A popular later account claims the Prophet ﷺ himself turned mid-prayer when Jibril AS interrupted him in his own masjid; the authentic reports instead describe the change being announced between Fajr and Zuhr, with only Banu Salama's congregation turning mid-salah on hearing the news secondhand.
On the day the qibla changed, the Prophet ﷺ prayed Fajr in his own masjid facing Jerusalem, then announced the change and prayed Zuhr facing Makkah: the change was announced between prayers, not mid-salah. Those who had prayed Zuhr with him were then meant to carry the news to their own people. The companion tasked with informing the masjid of Banu Salama arrived late; by the time he reached them, they were already praying Asr, so he called out from the back of the mosque, "O people of the masjid! I have just come from the Prophet's ﷺ Masjid, and I prayed with him Zuhr, and he was praying facing Makkah! The command has come to change direction!" The entire congregation turned together, mid-prayer, with the imam walking straight through the rows to the new front.
This became known as Masjid al-Qiblatayn (Mosque of the Two Qiblas) because it, uniquely, physically turned direction mid-salah, unlike the Prophet ﷺ's own masjid, where the change happened administratively between prayers.
Other events recorded in 2 AH. Their order within the year is not established; use the storyline above for the sequence.
O people of the masjid! I have just come from the Prophet's ﷺ Masjid, and I prayed with him Zuhr, and he was praying facing Makkah! The command has come to change direction!