‏الأيمان : Hadeeth No:4064 Abu Haraira reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying: Your oath should be about something regarding which your companion will believe you. 'Amr said: By which your companion will believe you....

‏الحج : Hadeeth No:3216 Ibn Umar narrated from Allaah's Prophet (sallAllaahu alayhi wa sallam) a hadlth like this....