Abu Musa sought permission to enter Umar's presence three times, but finding him apparently occupied, he turned back. Umar then said, "Did I not hear the voice of Abdullah bin Qays? Let him in." When Abu Musa was summoned, Umar asked him, "What made you do what you did?"Abu Musa replied, "We were instructed to act this way."Umar said, "You must bring me proof of this, or else I will deal with you."So Abu Musa went out and made his way to a gathering of the Ansar. They said to him, "None will testify on your behalf about this except the youngest among us." Abu Saeed then stood up and said, "We were indeed instructed to do this."Umar remarked, "This matter of the Messenger of Allah's ﷺ command was hidden from me. My trading in the markets distracted me from learning of it."
أن أبا موسى، استأذن على عمر ثلاثا، فكأنه وجده مشغولا، فرجع فقال عمر: ألم تسمع صوت عبد الله بن قيس، ائذنوا له، فدعي له، فقال: ما حملك على ما صنعت، قال: إنا كنا نؤمر بهذا قال: لتقيمن على هذا بينة أو لأفعلن، فخرج فانطلق إلى مجلس من الأنصار، فقالوا: لا يشهد لك على هذا إلا أصغرنا، فقام أبو سعيد فقال: كنا نؤمر بهذا، فقال عمر: خفي علي هذا من أمر رسول الله ﷺ ألهاني عنه الصفق بالأسواق.
Bukhari narrated it in the Book of Holding Fast (7353), and Muslim in the Book of Manners (2153:36), both from the hadith of Yahya bin Saeed Qattan, from Ibn Jurayj, who said, Ata narrated to us, from Ubayd bin Umayr, and he related it. Abu Dawud narrated it (5182) through Rawh bin Ubada, from Ibn Jurayj with the same chain, and he added, "But offer greetings as much as you wish, and do not ask permission to enter" after his statement, "I was distracted from it by trading in the markets." Its chain is sahih.It is also reported by Abu Dawud (5183) and Ibn Hibban (5806) through another route that Umar said to Abu Musa, "I did not suspect you, but reporting hadith from the Messenger of Allah ﷺ is a serious matter."