‏الآداب : Hadeeth No:5372 Jarir b. 'Abdullah reported: I asked Allaah's Messenger (sallAllaahu alayhi wa sallam) about the sudden glance (that is cast) on the face (of a non-Mahram). He commanded me that I should turn away my eyes....

‏النكاح : Hadeeth No:3287 Ibn Umar (Allaah be pleased with them) reported Allaah's Prophet (sallAllaahu alayhi wa sallam) as having said this: A person should not enter into a transaction when his brother (had already entered into but not finalised), and he should not make proposal of marriage upon the proposal already made ...