Musannaf Ibn Abi Shaybah 7390 — A man who prays Fajr and then finds

Ibn Sirin said: I have been told that Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) repeated the Fajr prayer three times in one day. He prayed and sat down, and it became clear that he had prayed before dawn, so he repeated the prayer. Then he prayed and sat down, and it became clear that dawn had still not broken, so he prayed it a third time.