Nafi’ narrates that it is reported from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: The month is (29) days, but do not begin fasting the month of Ramadan until you see the crescent, and do not stop fasting until you see (the Shawwal) crescent. If the sky is cloudy, then complete the count. Nafi’ says that the practice of Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) was that when it was the (29th) of Sha’ban, he would send some people to look for the crescent; if the crescent was sighted, that was best, and if it was not sighted and there was neither cloud nor dust, then he would not fast the next day. But if the sky was dusty or cloudy, then he would fast.