Some of the companions of the Messenger of Allah ﷺ reported that a group of riders came to the Prophet ﷺ testifying that they had sighted the crescent moon the day before. He instructed them to break their fast, and when morning came, to proceed to their prayer ground.
حدثنا حفص بن عمر حدثنا شعبة عن جعفر بن أبي وحشية عن أبي عمير بن أنس
له من أصحاب رسول الله ﷺ أن ركبا جاءوا إلى النبي ﷺ يشهدون أنهم رأوا الهلال بالأمس فأمرهم أن يفطروا وإذا أصبحوا أن يغدوا إلى مصلاهم
[Its isnad is sahih] Nasai reported it in "The Two Eids," chapter on going out for the two Eids on the following day, no. 1558, from the hadith of Shubah, through this route. Ibn Majah also narrated it, no. 1653, and Bayhaqi, 3/316, and others graded it sahih.