From the Jadilah of Qays, it is reported that the governor of Mecca delivered a sermon and said, "The Messenger of Allah ﷺ charged us to perform the rites upon sighting the moon. If we do not see it ourselves but two trustworthy witnesses testify to having seen it, we perform the rites based on their testimony."I asked Husayn bin Harith who the governor of Mecca was, and he said, "I do not know." Then he met me later and said, "He was Harith bin Hatib, the brother of Muhammad bin Hatib."The governor then said, "Among you is one who knows Allah and His Messenger better than I do, and he witnessed this from the Messenger of Allah ﷺ," gesturing with his hand toward a man.Husayn said, I asked an elder beside me, "Who is this that the governor pointed to?"He replied, "This is Abdullah bin Umar."He spoke truthfully, for he was indeed more knowledgeable about Allah than the governor was. So Abdullah bin Umar said, "This is what the Messenger of Allah ﷺ commanded us to do."
حدثنا محمد بن عبد الرحيم أبو يحيى البزاز حدثنا سعيد بن سليمان حدثنا عباد عن أبي مالك الأشجعي
من جديلة قيس أن أمير مكة خطب ثم قال عهد إلينا رسول الله ﷺ أن ننسك للرؤية فإن لم نره وشهد شاهدا عدل نسكنا بشهادتهما فسألت الحسين بن الحارث من أمير مكة قال لا أدري ثم لقيني بعد فقال هو الحارث بن حاطب أخو محمد بن حاطب ثم قال الأمير إن فيكم من هو أعلم بالله ورسوله مني وشهد هذا من رسول الله ﷺ وأومأ بيده إلى رجل قال الحسين فقلت لشيخ إلى جنبي من هذا الذي أومأ إليه الأمير قال هذا عبد الله بن عمر وصدق كان أعلم بالله منه فقال بذلك أمرنا رسول الله ﷺ
[Its chain of transmission is hasan] Daraqutni reported it in 2/167, hadith no. 2172, from the hadith of Saeed bin Sulayman with this chain, and he said, "This is a connected, sahih chain."