Two Prayers the Prophet s.a.w. never left

Narrated 'Aisha r.a. : The Prophet s.a.w. never left 

4 Rak'at before the Zuhr prayer and
2 Rak'at before the Fajr prayer

[ Reported by Al - Bukhari ]

( Ref : Bulugh Al- Maram, The Book of Prayer,  no. 282 )