مُوَطَّأُ مَالِكٍ
Muwatta Malik 185
Prayer
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يَقْرَأُ فِي الصُّبْحِ فِي السَّفَرِ بِالْعَشْرِ السُّوَرِ الأُوَلِ مِنَ الْمُفَصَّلِ فِي كُلِّ رَكْعَةٍ بِأُمِّ الْقُرْآنِ وَسُورَةٍ .
Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to recite the first ten suras of the mufassal in the subh prayer, and on a journey he would recite the ummal-Qur'an and a sura in every raka.
Arabic/English book reference: Book 3, Hadith 38