The Messenger of Allah (PBUH) saw a man praying the two supererogatory rak'ahs of Al-Fajr after establishing call (iqamah) of the -prescribed- Al-Fajr prayer, so he asked him (Epiplexis): Which of your prayers you intended to be counted -as the prescribed Al-Fajr prayer? The one you prayed alone or the one you prayed with us?