"a man entered the masjid, and the Messenger of Allah ﷺ was sitting in a corner of the mosque. He prayed, then he came and greeted him with Salam(peace), and he said: 'Wa 'alaikassalm."
أَنَّ رَجُلاً دَخَلَ الْمَسْجِدَ وَرَسُولُ اللَّهِ ﷺ جَالِسٌ فِي نَاحِيَةِ الْمَسْجِدِ فَصَلَّى ثُمَّ جَاءَ فَسَلَّمَ فَقَالَ وَعَلَيْكَ السَّلاَمُ