Arabic (Original)
حَدَّثَنَا عَبْدُ الصَّمَدِ حَدَّثَنِي أَبِي حَدَّثَنَا عَبْدُ الْعَزِيزِ يَعْنِي ابْنَ صُهَيْبٍ عَنْ أَبِي غَالِبٍ عَنْ أَبِي أُمَامَةَ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يُصَلِّيهِمَا بَعْدَ الْوِتْرِ وَهُوَ جَالِسٌ يَقْرَأُ فِيهِمَا إِذَا زُلْزِلَتْ الْأَرْضُ وَقُلْ يَا أَيُّهَا الْكَافِرُونَ.
English Translation
Abd al-Samad told us, my father told me, Abd al-Aziz -- meaning Ibn Suhayb -- told us, from Abu Ghalib, from Abu Umamah, that the Prophet, peace and blessings be upon him, used to pray them [two rak'ahs] after the Witr prayer, sitting, reciting in them "When the earth is shaken" and "Say, O disbelievers."