عَنْ عُمَرَ بْنِ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ الْحَارِثِ عَنْ أَبِيهِ أَنَّ عَمَّارًا (يَعْنِي بْنَ يَاسِرٍ) رَضِيَ اللَّهُ عَنْهُ صَلَّى رَكْعَتَيْنِ فَقَالَ لَهُ عَبْدُ الرَّحْمَنِ بْنُ الْحَارِثِ: يَا أَبَا الْيَقْظَانِ! لَا أَرَاكَ إِلَّا خَفَّفْتَهُمَا، قَالَ: هَلْ نَقَصْتُ مِنْ حُدُودِهَا شَيْئًا؟ قَالَ: لَا، وَلَٰكِنْ خَفَّفْتَهُمَا، قَالَ: إِنِّي بَادَرْتُ بِهِمَا السَّهْوَ، إِنِّي سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَقُولُ: ((إِنَّ الرَّجُلَ لَيُصَلِّي وَلَعَلَّهُ أَنْ لَا يَكُونَ لَهُ مِنْ صَلَاتِهِ إِلَّا عُشْرُهَا أَوْ تُسْعُهَا أَوْ ثُمَنُهَا أَوْ سُبُعُهَا، … )) حَتَّى انْتَهَى إِلَى آخِرِ الْعَدَدِ
Sayyiduna Ammar bin Yasir (may Allah be pleased with him) performed two rak‘ahs of prayer. Abdur Rahman bin Harith said to him: O Abu al-Yaqzan! I think you have shortened them. He replied: Have I omitted anything from its prescribed limits and conditions? He said: No, but you have shortened them. He said: (The real matter is that) I performed them quickly before I became forgetful, because I heard the Messenger of Allah (peace and blessings be upon him) say: Indeed, a man performs prayer, but it may be that nothing of his prayer is recorded for him except a tenth part, or a ninth part, or an eighth part, or a seventh part, ... until the Messenger of Allah (peace and blessings be upon him) reached the last number.