Musnad Ahmad 962:57

'Affan narrated to us, Aban narrated to us, Yahya ibn Abi Kathir narrated to us, from Zayd, from Abu Sallam, from Abu Umamah al-Bahili, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Recite the Quran, for it will come as an intercessor on the Day of Resurrection for its companion. Recite the two radiant ones: Al-Baqarah and Al-'Imran, for they will come on the Day of Resurrection as if they are two shades, or as if they are two clouds, or as if they are two flocks of birds in ranks, pleading for their companions. Recite Surah Al-Baqarah, for taking it is a blessing, and leaving it is a regret, and the sorcerers (al-batalah) cannot withstand it."