Muwatta Malik 482
موطأ مالك#482Da'ifThese are the words of a Companion, not of the Prophet ﷺ. The chain is graded on its own terms.
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
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 15:13