One Rakat before the sun rises
In the name of Allah, the most Beneficent, the most Merciful.
The full transcript of the hadith is that Saaiduna Abu Hurairah (ra) narrates that the Prophet of Allah (Pbuh) has said “Whoever find one rakat of Fajr prayer before the Sun rises he has found his Fajr prayer and whoever finds one rakat of Asr prayer before the sun sets he has found the Asr prayer.” (Sunan Tirmizi P45 v1)
There is an unanimous view that whilst performing Asr Salah if the sun sets in between the Asr Salah would be done. However Imam Tahawi (RA) has said that ones Asr Salah will be annulled.
With regards to the first part of the hadith there are differences of opinions. Imam Shafi, Imam Malik and Imam Ahmad Ibn Hanbal Rahmatuallahi Alayhim have said that the same way ones Asr Salah is done similarly a person whilst reading his Fajr prayer if the sun rises his Fajr Salah would be done. Imam Abu Hanifa Rahmatullahi Alayhi has said that ones Fajr Salah would not be accepted.
Mufti Taqi Uthmani (DB) in his Dars Tirmizi has written that the hadith (which I have mentioned above) contradicts the view of the Hanafi Fiqh and many answers have been given to reconcile the Hanafi viewpoint according to this hadith however a content answer or reconciliation has not been given. Therefore Moulana Rashid Ahmad Gonghohi (ra) has said that one should avoid giving different interpretations to this hadith and openly say that the Hanafi viewpoint with regard to the issue is against our understanding. Hence if a person begins his Fajr Salah prior to the sun rising and completes it whilst the sun is rising the Salah will be done. (Dars Tirmizi p.433-p.440 v.1)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham