Musnad Ahmad 459:20

Yazid ibn Abd Rabbih narrated to us, Baqiyyah ibn al-Walid narrated to us, he said: Buhayr ibn Sa’d narrated to me, from Khalid ibn Ma’dan, from Ibn Abi Bilal, from Irbad ibn Sariyah, that he narrated to them that the Messenger of Allah (peace and blessings of Allah be upon him) used to recite the *Musabbihat* (the chapters beginning with the glorification of Allah) before he would go to sleep. And he said: "Indeed, there is a verse in them that is better than a thousand verses."