Musnad Ahmad 2537

Hanzalah as-Sadoosi narrated: I said to ‘Ikrimah: In Maghrib prayer I recite Qul A'oodhu bi Rabbil-falaq and Qul A'oodhu bi Rabbin-Nas, and some people criticise me for that. He said: What is wrong with that? Recite them, for they are from the Qur'an. Then he said: Ibn 'Abbas (رضي الله عنه) told me that the Messenger of Allah (ﷺ) came and prayed two rak’ahs in which he did not recite anything but the Essence of the Book (i.e., al-Fatihah).