عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: صَلَاتَانِ لَمْ يَتْرُكْهُمَا النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ سِرًّا وَلَا عَلَانِيَةً رَكْعَتَيْنِ بَعْدَ الْعَصْرِ وَرَكْعَتَيْنِ قَبْلَ الْفَجْرِ
It is narrated from Sayyidah Aisha (may Allah be pleased with her), she says: There are two prayers which the Messenger of Allah (peace and blessings be upon him) never abandoned, neither secretly nor openly, that is, two rak'ahs after Asr and two rak'ahs before Fajr.