By Allah, Who took away the Prophet, the Prophet never missed them (two Rakat) after the ‘Asr prayer till he met Allah and he did not meet Allah till it became heavy for him to pray while standing so he used to offer most of the prayers while sitting. (She meant the two Rakat after Asr) He used to pray them in the house and never prayed them in the mosque lest it might be hard for his followers and he loved what was easy for them.
Narrated Hisham’s father:
‘Aisha (addressing me) said, “O son of my sister! The Prophet never missed two prostrations (i.e. Rakat) after the ‘Asr prayer in my house.”
Allah’s Apostle never missed two Rakat before the Fajr prayer and after the Asr prayer openly and secretly.
Whenever the Prophet come to me after the ‘Asr prayer, he always prayed two Rakat.
So, if it’s a prayer of ‘sabab‘ (reason) like janazah or qadha prayer, one may pray after ‘Asr (before sunset). This is an exception. Normally, it’s not allowed to pray at that time, as mentioned in the previous two posts.
These two rak’aat (as mentioned in Ahadith) that the Prophet (SAW) never missed, were specific for the Prophet (SAW) only. Just like offering tahajjud was mandatory for him, but it’s optional for us.