Narrated AbuUmayr ibn Anas: AbuUmayr reported on the authority of some of his paternal uncles who were Companions of the Prophet (ﷺ): Some men came riding to the Prophet (ﷺ) and testified that they had sighted the new moon the previous day. He (the Holy Prophet), therefore, commanded the people to break the fast and to go out to their place of prayer in the morning

English translation · Sunan Abu Dawud