Abu Musa asked ʿUmar to admit him but he was not admitted as ʿUmar was busy, so Abu Musa went back. When ʿUmar finished his job he said, "Didn't I hear the voice of ʿAbdullah bin Qais? Let him come in." ʿUmar was told that he had left. So, he sent for him and on his arrival, he (Abu Musa) said, "We were ordered to do so (i.e. to leave if not admitted after asking permission thrice). ʿUmar told him, "Bring witness in proof of your statement." Abu Musa went to the Ansar's meeting places and asked them. They said, "None amongst us will give this witness except the youngest of us, Abu Saʿid Al-Khudri. Abu Musa then took Abu Saʿid Al-Khudri (to ʿUmar) and ʿUmar said, surprisingly, "Has this order of Messenger of Allah ﷺ been hidden from me?" (Then he added), "I used to be busy trading in markets."  

وَكَأَنَّهُ كَانَ مَشْغُولاً فَرَجَعَ أَبُو مُوسَى فَفَرَغَ عُمَرُ فَقَالَ أَلَمْ أَسْمَعْ صَوْتَ عَبْدِ اللَّهِ بْنِ قَيْسٍ ائْذَنُوا لَهُ قِيلَ قَدْ رَجَعَ فَدَعَاهُ فَقَالَ كُنَّا نُؤْمَرُ بِذَلِكَ فَقَالَ تَأْتِينِي عَلَى ذَلِكَ بِالْبَيِّنَةِ فَانْطَلَقَ إِلَى مَجْلِسِ الأَنْصَارِ فَسَأَلَهُمْ فَقَالُوا لاَ يَشْهَدُ لَكَ عَلَى هَذَا إِلاَّ أَصْغَرُنَا أَبُو سَعِيدٍ الْخُدْرِيُّ فَذَهَبَ بِأَبِي سَعِيدٍ الْخُدْرِيِّ فَقَالَ عُمَرُ أَخَفِيَ عَلَىَّ مِنْ أَمْرِ رَسُولِ اللَّهِ ﷺ أَلْهَانِي الصَّفْقُ بِالأَسْوَاقِ يَعْنِي الْخُرُوجَ إِلَى تِجَارَةٍ