Sahih Bukhari Volume 4, Book 54, Hadith Number 433.

Narated By Abu Huraira : The Prophet said, “On every Friday the angels take heir stand at every gate of the mosques to write the names of the people chronologically (i.e. according to the time of their arrival for the Friday prayer and when the Imam sits (on the pulpit) they fold up their scrolls and get ready to listen to the sermon.”