‏العلم : Hadeeth No:6450 Abdullah reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying: Ruined, were those who indulged in hair-splitting. He (the Prophet) repeated this thrice....

‏الصيام : Hadeeth No:2365 This hadith is narrated on the authority of 'Ubaidullah with the same chain of transmitters, and he said: If (the sky) is cloudy for you, then calculate thirty days (for the month of Ramadan)....