A Hadith from Shahih-Al-Bhukhari states that
"Aa’ishah (ra) said: Anytime God’s messenger (pbuh) came to my house
after the Asr he prayed two Rak’ah." (Bukhari, 593)
The scholars of Islam have tried to find a reconciliation between Hadiths like the above and the ones that narrate that the Prophet (pbuh) forbade reading prayers after the Asr, however there is no agreement on this. Some believe that the Prophet (pbuh) did not continue to read this prayer. Others believe that the Prophet (pbuh) read it for a specific reason (i.e. missing the after-the- Zuhr- non-obligatory prayers) but then continued reading it regularly because once he read it, as a prophet, he would make it upon himself to make it his habit and to read it every day. Others consider this prayer to be specific to the Prophet (pbuh). Then there are those who believe that the directives that forbid reading prayers after Asr have abrogated the allowance that can be derived from the above Hadith. However, others have said the opposite, i.e. it is the above allowance that have abrogated the forbidding directives.
- Refer to Fat'h al-Bari, Sharh al-Bukhari by Ibn Rajab, 5:78-100
The above is perhaps one of the reasons that the four famous schools of Fiqh have different views about reading Nafl after Asr.
There are another groups of Hadiths that narrate that the Prophet (pbuh) prohibited praying and burying the dead during sunrise and sunset and when the sun is in its meridian. It is likely that the Hadiths that forbid reading prayers after the Subh prayer and after the Asr prayer in fact refer to the times when it gets very close to sunset or sunrise.