مُوَطَّأُ مَالِكٍ
Muwatta Malik 485
The Qur'an
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، مَوْلَى ابْنِ عُمَرَ أَنَّ رَجُلاً، مِنْ أَهْلِ مِصْرَ أَخْبَرَهُ أَنَّ عُمَرَ بْنَ الْخَطَّابِ قَرَأَ سُورَةَ الْحَجِّ فَسَجَدَ فِيهَا سَجْدَتَيْنِ ثُمَّ قَالَ إِنَّ هَذِهِ السُّورَةَ فُضِّلَتْ بِسَجْدَتَيْنِ .
Yahya related to me from Malik from Nafi, the mawla of Ibn Umar that a man from Egypt told him that Umar ibn al-Khattab recited Surat al-Hajj (Sura 22) and prostrated twice in it, and then said, "This sura has been given special preference by having two prostrations in it."
Arabic/English book reference: Book 15, Hadith 13