Hadith 19868

حَدَّثَنَا مُعْتَمِرٌ ، عَنْ خَالِدٍ ، عَنْ أَبِي قِلَابَةَ ، عَنْ أَبِي الْمُهَلَّبِ ، عَنْ عِمْرَانَ بْنِ حُصَيْنٍ , أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " صَلَّى ثَلَاثَ رَكَعَاتٍ ، فَسَلَّمَ ، فَقِيلَ لَهُ ، فَقَامَ فَصَلَّى رَكْعَةً ، فَسَلَّمَ ، ثُمَّ سَجَدَ سَجْدَتَيْنِ وَهُوَ جَالِسٌ " .
It is narrated from Hazrat Imran bin Husain (may Allah be pleased with him) that once the Prophet (peace and blessings be upon him) ended the Asr prayer after three rak'ahs. When people drew his attention to it, the Prophet (peace and blessings be upon him) stood up and performed the missed rak'ah, then after saying salam, he performed two prostrations of forgetfulness while sitting, and then said salam again.
Hadith Reference مسند احمد / أول مسند البصريين / 19868
Hadith Grading حکم دارالسلام: إسناده صحيح، م: 574