"The angels send Salah upon any one of you so long as he is in the place where he prays, and so long as he does not invalidate his ablution, (saying): 'O Allah, forgive him, O Allah, have mercy on him.'"  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِنَّ الْمَلاَئِكَةَ تُصَلِّي عَلَى أَحَدِكُمْ مَا دَامَ فِي مُصَلاَّهُ الَّذِي صَلَّى فِيهِ مَا لَمْ يُحْدِثِ اللَّهُمَّ اغْفِرْ لَهُ اللَّهُمَّ ارْحَمْهُ  

"I heard the Messenger of Allah ﷺ say: 'Whoever is in the Masjid waiting for the prayer, he is in a state of prayer.'"  

قَالَ سَمِعْتُ سَهْلاً السَّاعِدِيَّ ؓ يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ مَنْ كَانَ فِي الْمَسْجِدِ يَنْتَظِرُ الصَّلاَةَ فَهُوَ فى الصَّلاَةِ