Musnad Abu Ya'la al-Mawsili 115:74

Narrated to us Abd al-Rahman ibn Salam, narrated to us Hammad ibn Salamah, narrated to us Qatadah, Thabit, and Humayd, from Anas: That the Messenger of Allah (peace and blessings of Allah be upon him) was leading them in prayer, and a man came and entered the prayer while he was out of breath. He said: "Allah is the Greatest, praise be to Allah, much, good, and blessed praise therein." When the Messenger of Allah (peace and blessings of Allah be upon him) finished his prayer, he said: "Which of you spoke the words?" The people remained silent. He said: "Which of you spoke the words? For he did not say anything wrong." The man said: "I did, O Messenger of Allah. I came while I was out of breath, so I said them." He said: "I saw twelve angels rushing to see which of them would raise them up."