Hadith 598

(حديث مرفوع) حَدَّثَنَا عَبْد اللَّهِ ، حَدَّثَنِي أَبُو كُرَيْبٍ مُحَمَّدُ بْنُ الْعَلَاءِ ، حَدَّثَنَا ابْنُ الْمُبَارَكِ ، عَنْ يَحْيَى بْنِ أَيُّوبَ ، عَنْ عُبَيْدِ اللَّهِ بْنِ زَحْرٍ ، عَنْ عَلِيِّ بْنِ يَزِيدَ ، عَنِ الْقَاسِمِ ، عَنْ أَبِي أُمَامَةَ ، قَالَ : قَالَ عَلِيٌّ رَضِيَ اللَّهُ عَنْهُ : كُنْتُ آتِي النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، فَأَسْتَأْذِنُ ، " فَإِنْ كَانَ فِي صَلَاةٍ سَبَّحَ ، وَإِنْ كَانَ فِي غَيْرِ صَلَاةٍ أَذِنَ لِي " .
Sayyiduna Ali (may Allah be pleased with him) narrates that when I used to come to the service of the Prophet (peace and blessings be upon him), if the Prophet (peace and blessings be upon him) was standing and performing prayer at that time, he would say "Subhan Allah"; this would be a sign that I was permitted to enter. And if the Prophet (peace and blessings be upon him) was not performing prayer at that time, he would simply grant permission (and there would be no need to say "Subhan Allah").
Hadith Reference مسند احمد / مسند الخلفاء الراشدين / 598
Hadith Grading حکم دارالسلام: إسناده مسلسل بالضعفاء