"While the people were in Quba praying Subh prayer, someone came to them and said that revelation had come to Messenger of Allah ﷺ the night before, and he had been commanded to face Ka'bah. So face toward it. They had been facing toward Ash-Sham, so they turned to face toward Ka'bah."
بَيْنَمَا النَّاسُ بِقُبَاءٍ فِي صَلاَةِ الصُّبْحِ جَاءَهُمْ آتٍ فَقَالَ إِنَّ رَسُولَ اللَّهِ ﷺ قَدْ أُنْزِلَ عَلَيْهِ اللَّيْلَةَ قُرْآنٌ وَقَدْ أُمِرَ أَنْ يَسْتَقْبِلَ الْقِبْلَةَ فَاسْتَقْبَلُوهَا وَكَانَتْ وُجُوهُهُمْ إِلَى الشَّامِ فَاسْتَدَارُوا إِلَى الْكَعْبَةِ