Abu Hurayra reported that the Messenger of Allah, may Allah bless
him and grant him peace, forbade people to sit in courtyards and roads.
The Muslims said, "We will not be able to avoid it. We cannot undertake
it." He said, "If not, then give it its due." They said, "What is it due?"
He said, "Lower the eye, guide the traveller, wish for mercy on the person
who sneezes when he praises Allah and return the greeting."
'Abdullah ibn 'Amr reported that a man said, "Messenger of Allah,
which aspect of Islam is best?" He replied, "Feeding people and greeting
those you know and those you do not know."
Abu Hurayra said, "The most miserly of people is the person who
is miserly with the greeting. The one who is cheated of good is the one
who does not return it. if a tree comes between you and your brother, and
you are able to be the first to begin the greeting before the other person,
then do it."