And none should ask for the hand of a girl who is already engaged to his (Muslim) brother, but one should wait till the first suitor marries her or leaves her."

Narrated Abu Huraira: Allah's Apostle forbade the selling of things by a town dweller on behalf of a desert dweller; and similarly Najsh was forbidden. And one should not urge somebody to return the goods to the seller so as to sell him his own goods; nor should one demand the hand of a girl who has already been engaged to someone else; and a woman should not try to cause some other woman to be divorced in order to take her place.

Narrated Abu Huraira: The Prophet said, "Beware of suspicion, for suspicion is the worst of false tales; and do not look for the others' faults and do not spy, and do not be jealous of one another, and do not desert (cut your relation with) one another, and do not hate one another; and O Allah's worshipers! Be brothers (as Allah has ordered you!")

Narrated Abu Huraira: Allah's Apostle said, "Beware of suspicion, for suspicion is the worst of false tales. and do not look for the others' faults, and do not do spying on one another, and do not practice Najsh, and do not be jealous of one another and do not hate one another, and do not desert (stop talking to) one another. And O, Allah's worshipers! Be brothers!"

Narrated Abu Huraira: Allah's Apostle said, 'Beware of suspicion, for it is the worst of false tales and don't look for the other's faults and don't spy and don't hate each other, and don't desert (cut your relations with) one another O Allah's slaves, be brothers!" (See Hadith No. 90)