ENOfficial
Abu Hurairah reported the Messenger of Allah (May peace be upon him) as saying; The angels invoke blessings on any of you who remains sitting at the place where he says his prayers so long as he is defiled (needs ablution) or stands up, saying: O Allah, forgives him; O Allah, have mercy on him.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " الْمَلاَئِكَةُ تُصَلِّي عَلَى أَحَدِكُمْ مَا دَامَ فِي مُصَلاَّهُ الَّذِي صَلَّى فِيهِ مَا لَمْ يُحْدِثْ أَوْ يَقُمِ اللَّهُمَّ اغْفِرْ لَهُ اللَّهُمَّ ارْحَمْهُ " .
sunnah.com