The companions of the Prophet (pbuh) knew of the
thawaabs of being the first ones to say ‘Assalamu ‘alaykum’ to
someone. The Prophet (pbuh) had said that the one who
initiates salaam gets ninety nine thawaabs although it is
mustahab and the one who replies would get one even
though the reply is wajib.
However, the Prophet (pbuh) was always the first to greet
them.
This time, the companions thought they would beat him to it.
As they saw the Prophet (pbuh) approaching, they hid in the
doorways of the alley towards which he was coming, hoping
that as soon as he came they would surprise him and greet
him first.
As soon as the Prophet (pbuh) came to the entrance of the
alley, he called out in a loud voice:
“My salaams to all those in this alley way.”
Excellent Stories Vol 1