Musannaf Ibn Abi Shaybah

Hazrat Yazid narrated that Hazrat Ali (may Allah be pleased with him) used to ask Ibn Nabah, "Has the sun set?" He would reply, "Do not hurry." He would ask again, "Has the sun set?" and he would say, "Do not hurry." Hazrat Ali (may Allah be pleased with him) would ask again, "Has the sun set?" When Ibn Nabah said that the sun had set, he broke his fast and then descended to perform the prayer.