সুনানে ইবনে মাজাহ ১৬৫১

It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said:‘Do not anticipate Ramadan by fasting one or two days before, except for a man who has a habitual pattern of fasting, in which case let him fast.”

It was narrated that Ibn ‘Abbas said:“A Bedouin came to the Prophet (ﷺ) and said: ‘I have seen the new crescent tonight.’ He said: ‘Do you bear witness that none has the right to be worshipped but Allah and that Muhammad is the Messenger of Allah (ﷺ)?’ He said: ‘Yes.’ He said: ‘Get up, O Bilal, and announce to the people that they should fast tomorrow.’” Abu 'Ali said: "This is how it was narrated from Walid bin Abu Thawr and Hasan bin 'Ali. It was also narrated from Hammad bin Salamah, but he did not mention Ibn 'Abbas. He said: 'And he announced that they should perform the prayer and that they should fast

It was narrated that ‘Umair bin Anas bin Malik said:“My paternal uncles among the Ansar who were among the Companions of the Messenger of Allah (ﷺ) told me: ‘The new crescent of Shawwal was covered with clouds, so we fasted the next day. Then some riders came at the end of the day and testified to the Prophet (ﷺ) that they had seen the new crescent the night before. The Messenger of Allah (ﷺ) commanded them to break their fast and to go out to offer the ‘Eid prayer the following morning.’”