Musannaf Ibn Abi Shayba 3:5944

Mu'tamir narrated to us, from Ishaq bin Suwayd, from al-'Ala' bin Ziyad, regarding the eclipse prayer, he said: He stands and recites, and bows. Then, when he says, "Allah hears those who praise Him," he looks at the moon. If it has not cleared, he recites, then bows, then raises his head. Then, when he says, "Allah hears those who praise Him," he looks at the moon. If it has cleared, he prostrates, then stands and completes it with a rak'ah. And if it has not cleared, he does not prostrate at all until it clears, whenever it may clear. Then, if there is an eclipse afterward, he does not pray this prayer.