The Messenger of Allah ﷺ said, "At every door of the mosque stands an angel who records those who come, the first then the next. The first is like one who offers a camel as a sacrifice," and he continued ranking them down until he reached the equivalent of an egg. "When the imam sits, the pages are folded up, and the angels attend the remembrance."
أن رسول الله ﷺ قال: على كل باب من أبواب المسجد ملك يكتب: الأول فالأول (مثل الجزور، ثم نزلهم حتى صغر إلى مثل البيضة) فإذا جلس الإمام طويت الصحف، وحضروا الذكر.