Maliks Muwatta Book 3, Hadith Number 27.

Section : The Recitation of Qur’an in the Maghrib and Isha Prayers.

Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to recite in all four rakas as when he prayed alone – in every raka the umm al-Qur’an and another sura from the Qur’an. Sometimes he would recite two or three suras in one raka in the obligatory prayer. Similarly, he recited the umm al-Qur’an and two suras in the first two rakas of maghrib.