The Messenger of Allah ﷺ said, "Do not let any of you be kept from his pre-dawn meal by Bilal's call to prayer, for he calls out," or he said, "he announces, so that the one standing in prayer may return and the one sleeping may be roused. The true dawn is not when it appears like this," and Yahya brought his palms together, "but rather when it appears like this," and Yahya extended his two index fingers.
حدثنا مسدد عن يحيى عن التيمي عن أبي عثمان
قال رسول الله ﷺ لا يمنعن أحدكم أذان بلال من سحوره فإنه يؤذن أو قال ينادي ليرجع قائمكم وينبه نائمكم وليس الفجر أن يقول هكذا وجمع يحيى كفيه حتى يقول هكذا ومد يحيى إصبعيه السبابتين