‏البيوع : Hadeeth No:3914 Abu Qatada al-Ansari (Allaah be pleased with him) reported he heard Allaah's Messenger (sallAllaahu alayhi wa sallam) say: Beware of swearing; it produces a ready sale for a commodity, but blots out the blessing....

‏الصيام : Hadeeth No:2614 Abu Ayyub al-Ansari (Allaah be pleased with him) reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying: He who observed the fast of Ramadan and then followed it with six (fasts) of Shawwal. it would be as if he fasted perpetually....