Musnad Ahmad 788:206

Yahya ibn Adam narrated to us, Isra'il narrated to us, from Abu Ishaq, from al-Aswad, who said: Abu Musa said: "Ali ibn Abi Talib, may Allah be pleased with him, reminded us of a prayer we used to perform with the Messenger of Allah, may Allah bless him and grant him peace—either we forgot it, or we abandoned it intentionally: he would say 'Allahu Akbar' every time he bowed, every time he rose, and every time he prostrated." *** Muhammad ibn al-Sabbah narrated to us—'Abdullah said: And I heard it myself from Muhammad ibn al-Sabbah—Isma'il ibn Zakariyya narrated to us, from Burayd, from Abu Burdah, from Abu Musa al-Ash'ari, who said: The Prophet, may Allah bless him and grant him peace, heard a man praising another man and exaggerating in his praise, so he said: "You have destroyed—or you have broken—the man's back."