Sünen-i İbn Mâce — Chapters on Food — Hadis No: 3321

It was narrated from Abu Hurairah that in the two Rak’ah before the Fajr, the Prophet (ﷺ) used to recite:“Say: ‘O you disbelievers!” [Al-Kafirun (109)] and “Say: Allah is One.” [Al-Ikhlas]

It was narrated that ‘Aishah said:“The Messenger of Allah (ﷺ) used to perform two Rak’ah before Fajr, and he used to say: ‘The best two Surah to recite in the two Rak’ah of Fajr are: “Say: Allah is One” [Al-Ikhlas (112)] and “Say: O you disbelievers.” [Al-Kafirun]

It was narrated that Qais bin ‘Amr said:“The Prophet (ﷺ) saw a man praying two Rak’ah after the Subh prayer and said, ‘Is the Subh prayer to be offered twice?’ The man said to him: ‘I did not pray the two Rak’ah before it, so I prayed them (now).’ The Messenger of Allah (ﷺ) remained silent.”

It was narrated from Abu Ayyub that the Prophet (ﷺ) used to perform four Rak’ah before the Zuhr when the sun had passed its zenith, and he did not separate them with a Taslim. He said, “The gates of heaven are opened when the sun passes its zenith.”