Sunan an-Nasa'i, Hadith 1557 ⓘ
It was narrated from 'Umair bin Anas from his paternal uncles, that : Some people saw the crescent moon and came to the Prophet, and he told them to break their fast after the sun has risen and to go out for 'Eid the (morning of the) following day.
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ حَدَّثَنَا أَبُو بِشْرٍ، عَنْ أَبِي عُمَيْرِ بْنِ أَنَسٍ، عَنْ عُمُومَةٍ، لَهُ أَنَّ قَوْمًا، رَأَوُا الْهِلاَلَ فَأَتَوُا النَّبِيَّ صلى الله عليه وسلم فَأَمَرَهُمْ أَنْ يُفْطِرُوا بَعْدَ مَا ارْتَفَعَ النَّهَارُ وَأَنْ يَخْرُجُوا إِلَى الْعِيدِ مِنَ الْغَدِ .
also referenced under: Book 19, Hadith 2 (In-Book) & Volume 2, Book 19, Hadith 1558 (DarusSalam)