Musannaf Ibn Abi Shayba 3:1369

Hafs ibn Ghiyath narrated to us, from Hajjaj, from Ibn al-Aswad, who said: He recites in the first two rak'ahs the Opening of the Book (al-Fatiha) and a surah. And in the last two, he performs tasbih (glorification) and takbir (magnification).