عَنْ عَطَاءِ بْنِ السَّائِبِ عَنْ أَبِي عَبْدِ الرَّحْمَنِ قَالَ: سَمِعْتُ عَلِيًّا يَقُولُ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((إِنَّ الْعَبْدَ إِذَا جَلَسَ فِي مُصَلَّاهُ بَعْدَ الصَّلَاةِ صَلَّتْ عَلَيْهِ الْمَلَائِكَةُ، وَصَلَاتُهُمْ عَلَيْهِ: اللَّهُمَّ اغْفِرْ لَهُ اللَّهُمَّ ارْحَمْهُ))
It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Indeed, when a servant remains seated in his place of prayer after performing the prayer, the angels supplicate for mercy for him, and their supplication for mercy is: "O Allah, forgive him. O Allah, have mercy on him."