Arabic (Original)
حَدَّثَنَا يَزِيدُ وَأَبُو النَّضْرِ قَالَا أَخْبَرَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ بْنِ أَبِي سَلَمَةَ عَنْ زَيْدِ بْنِ أَسْلَمَ عَنْ عَطَاءِ بْنِ يَسَارٍ عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِذَا شَكَّ أَحَدُكُمْ فِي الصَّلَاةِ فَلَمْ يَدْرِ ثَلَاثًا صَلَّى أَمْ أَرْبَعًا فَلْيَقُمْ فَلْيُصَلِّ رَكْعَةً قَالَ يَزِيدُ حَتَّى يَكُونَ الشَّكُّ فِي الزِّيَادَةِ ثُمَّ لِيَسْجُدْ سَجْدَتَيْ السَّهْوِ فَإِنْ كَانَ صَلَّى خَمْسًا شَفَعَتَا لَهُ صَلَاتَهُ وَإِنْ كَانَ صَلَّى أَرْبَعًا فَهُمَا يُرْغِمَانِ الشَّيْطَانَ.
English Translation
Yazid and Abu al-Nadr told us, they said: Abd al-Aziz ibn Abdullah ibn Abi Salama informed us, from Zayd ibn Aslam, from Ata' ibn Yasar, from Abu Sa'id al-Khudri, from the Prophet, peace and blessings be upon him, who said: "If one of you doubts in the prayer and does not know whether he prayed three or four, let him stand and pray one more raka'a" - Yazid said: "as long as the doubt is about an addition" - "then let him prostrate the two prostrations of forgetfulness. If he had prayed five, they will make his prayer even for him, and if he had prayed four, they will be a humiliation for Satan."