Lady Umm Salamah (may Allah be pleased with her) narrates that the Messenger of Allah (peace and blessings be upon him) came to me after the Asr prayer and performed two rak‘ahs. I asked,“O Messenger of Allah, which prayer is this? You do not usually perform this prayer.”The Messenger of Allah (peace and blessings be upon him) replied:“A delegation from Banu Tamim had come to me and they kept me busy from performing these two rak‘ahs which I usually perform after the Zuhr prayer.”I have mentioned the chains of this narration in Kitab al-Kabir. Imam Abu Bakr (may Allah have mercy on him) says that therefore the Prophet (peace and blessings be upon him) performed two rak‘ahs of Sunnah after the Asr prayer. He was making up for those two rak‘ahs which he used to perform after Zuhr. And if the Prophet (peace and blessings be upon him) had prohibited the performance of all voluntary prayers after Asr until sunset, then it would not have been permissible for him to make up those two rak‘ahs after Asr which he used to perform after Zuhr. Undoubtedly, the Prophet (peace and blessings be upon him) performed these two rak‘ahs as a voluntary act out of consistency and as a recommended practice, because he (peace and blessings be upon him) said:“Indeed, the best of deeds are those done consistently.”And whenever the Prophet (peace and blessings be upon him) did any deed, he liked to do it consistently.