Arabic (Original)
وَأَخْبَرَنَا أَبُو عَبْدِ اللهِ الْحَافِظُ وَأَبُو سَعِيدِ بْنُ أَبِي عَمْرٍو قَالَا ثنا أَبُو الْعَبَّاسِ مُحَمَّدُ بْنُ يَعْقُوبَ ثنا أُسَيْدُ بْنُ عَاصِمٍ ثنا الْحُسَيْنُ بْنُ حَفْصٍ عَنْ سُفْيَانَ عَنْ مَنْصُورٍ عَنْ إِبْرَاهِيمَ عَنِ الْأَسْوَدِ وَعَمْرِو بْنِ مَيْمُونٍ قَالَا صَلَّيْنَا خَلْفَ عُمَرَ الْفَجْرَ فَلَمْ يَقْنُتْ وَقَدْ رُوِّينَا فِي بَابِ الْقُنُوتِ عَنْ رَسُولِ اللهِ ﷺ ثُمَّ عَنِ الْخُلَفَاءِ بَعْدَهُ أَنَّهُمْ قَنَتُوا فِي صَلَاةِ الصُّبْحِ وَمَشْهُورٌ عَنْ عُمَرَ مِنْ أَوْجُهٍ صَحِيحَةٍ أَنَّهُ كَانَ يَقْنُتُ فِي صَلَاةِ الصُّبْحِ فَلَئِنْ تَرَكُوهُ فِي بَعْضِ الْأَحَايِينِ سَهْوًا أَوْ عَمْدًا دَلَّ ذَلِكَ عَلَى كَوْنِهِ غَيْرَ وَاجِبٍ وَحِينَ لَمْ يَنْقُلْ عَنْ أَحَدٍ مِنْهُمْ أَنَّهُ سَجَدَ سَجْدَتَيِ السَّهْوِ لِذَلِكَ دَلَّ عَلَى أَنَّهُ لَا سُجُودَ فِي السَّهْوِ عَنْهُ وَاللهُ أَعْلَمُ
English Translation
Al-Aswad and Amr ibn Maymun said: We prayed Fajr behind Umar and he did not perform the qunut. It has been narrated in the chapter on qunut from the Messenger of Allah (peace be upon him), and then from the Caliphs after him, that they performed qunut in the Fajr prayer. It is well-known from Umar through authentic chains that he used to perform qunut in the Fajr prayer. If they abandoned it sometimes, whether out of forgetfulness or intentionally, that indicates it is not obligatory. And since it has not been reported from any of them that they prostrated the two prostrations of forgetfulness for that, it indicates there is no prostration for forgetting it. And Allah knows best.