Is it permissible for me to shake the hand of my wife’s sister, and to be alone with her or other than that? [It’s just] because I know [while I am married to her sister, then] she is prohibited to me.
Extending the greeting by a nod of the head
Some people – [and] may Allaah guide them – when they pass by others who are seated or passing them, they nod their head towards them – intending [by doing so] to extend the greeting [of as-salaam ‘alaykum]; [so] should we respond to them [when they do this]?
Shaking hands with women
Is it permissible to shake the hand of a woman if doing so is from the custom of the people of the land?