‏الصيام : Hadeeth No:2363 Ibn Umar (Allaah be pleased with both of them) reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying in connection with Ramadan: Do not fast till you see the new moon, and do not break fast till you see it; but if the weather is cloudy calculate about it....

‏الصلاة : Hadeeth No:855 Anas b. Malik reported. The Messenger of Allaah (sallAllaahu alayhi wa sallam) said: Perform bowing and prostration well. By Allaah. I see you even if you are behind me, or he said'. (1 see you) behind my back when you bow or prostrate....