‏النكاح : Hadeeth No:3294 'Uqba b. 'Amir said on the pulpit that Allaah's Messenger (sallAllaahu alayhi wa sallam) said: A believer is the brother of a believer, so it is not lawful for a believer to outbid his brother, and he should not propose an engagement when his brother has thus proposed until he gives it up....

‏الزكاة : Hadeeth No:2231 Abu Musa reported Allaah's Prophet (sallAllaahu alayhi wa sallam) as saying: The honest Muslim trustee who spends (sometimes he said" who gives" ) what he is commanded to do and he gives that in full with his heart overflowing with cheerfulness and he gives it to one to whom he is ordered, he is one...