Muwatta Malik, Book 15, Hadith 15 (USC-MSA) ⓘ
Yahya related to me from Malik from Ibn Shihab from al-Araj that Umar ibn al Khattab recited Surat an-Najm (Sura 53) and prostrated in it, and then got up and recited another sura.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنِ الأَعْرَجِ، . أَنَّ عُمَرَ بْنَ الْخَطَّابِ، قَرَأَ بِالنَّجْمِ إِذَا هَوَى فَسَجَدَ فِيهَا ثُمَّ قَامَ فَقَرَأَ بِسُورَةٍ أُخْرَى .
also referenced under: Book 15, Hadith 487 (In-Book)