‏البيوع : Hadeeth No:3667 Ibn Umar (Allaah be pleased with them) reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying: Do not buy fruit until its good condition becomes clear, and (the danger) of blight is no more. He said: Its good condition becoming clear implies that it becomes red or yellow....

‏الصيام : Hadeeth No:2501 'A'isha (Allaah be pleased with her) reported. In the pre-Islamic days fast was observed on the day of Ashura, but with the advent of Islam (its position was ascertained as that of a voluntary fast). Then he who wished to fast fasted, and he who liked to abandon it abandoned it....