[Machine] I saw Umar ibn al-Khattab prostrating in the prayer of Fajr, then he began reciting another Surah.  

رَأَيْتُ عُمَرَ بْنَ الْخَطَّابِ ؓ سَجَدَ فِي النَّجْمِ فِي صَلَاةِ الْفَجْرِ ثُمَّ اسْتَفْتَحَ بِسُورَةٍ أُخْرَى  

[Machine] He said, "If the prostration (sujood) is at the end of the surah, then he may choose to perform a bowing (raka'a) or prostration (sujood)."  

أَنَّهُ قَالَ إِذَا كَانَتِ السَّجْدَةُ فِي آخِرِ السُّورَةِ فَإِنْ شَاءَ رَكَعَ وَإِنْ شَاءَ سَجَدَ  

[Machine] If he wants, he can perform the bowing and if he wants, he can perform the prostration, then he stands up, recites, bows, and prostrates.  

إِنْ شَاءَ رَكَعَ وَإِنْ شَاءَ سَجَدَ ثُمَّ قَامَ فَقَرَأَ وَرَكَعَ وَسَجَدَ  

[Machine] One of them prostrated when the sky split open and (said): recite (read) in the name of your Lord, Who created. Abdullah bin Mas'ud used to prostrate when he recited An-Najm (chapter 53) with the people, and when he recited it in prayer. Ibn 'Umar used to prostrate when he recited it in prayer, and if he did not recite it in prayer, he would bow. 'Uthman bin 'Affan used to prostrate when he recited it, then he would stand and recite At-Tin (chapter 95) and Az-Zaitun (chapter 76), or a surah that resembles them. The Prophet ﷺ also prostrated with it. And in the hadith of Al-Birti: if neither the Prophet ﷺ nor 'Umar bin Al-Khattab were (available).  

أَحَدُهُمَا سَجَدَ فِي إِذَا السَّمَاءُ انْشَقَّتْ وَفِي اقْرَأْ بِاسْمِ رَبِّكَ الَّذِي خَلَقَ قَالَ وَكَانَ عَبْدُ اللهِ بْنُ مَسْعُودٍ إِذَا قَرَأَ النَّجْمَ مَعَ الْقَوْمِ سَجَدَ وَإِذَا قَرَأَهَا فِي الصَّلَاةِ وَكَانَ ابْنُ عُمَرَ إِذَا وَصَلَ إِلَيْهَا قُرْآنًا سَجَدَ وَإِذَا لَمْ يَصِلْ إِلَيْهَا قُرْآنًا رَكَعَ وَكَانَ عُثْمَانُ بْنُ عَفَّانَ ؓ إِذَا قَرَأَهَا سَجَدَ ثُمَّ يَقُومُ فَيَقْرَأُ بِالتِّينِ وَالزَّيْتُونِ أَوْ سُورَةٍ تُشْبِهُهَا قَالَ وَسَجَدَ بِهَا النَّبِيُّ ﷺ وَفِي حَدِيثِ الْبِرْتِيِّ إِنْ لَمْ يَكُنِ النَّبِيُّ ﷺ أَوْ عُمَرُ بْنُ الْخَطَّابِ ؓ