Allah the Exalted says: When you are greeted with a greeting, greet in return with what is better than it.

Abdullah bin Amr (radi Allahu anhu) narrated: A man asked the Prophet (Sallallahu alaihi wasallam) “Whose Islam is better” The Prophet (Sallallahu alaihi wasallam) replied, “To feed (others), and say salam to whom you recognize and (also) whom you do not recognize.”

Abu Huraira (radi Allahu anhu) narrated: Allah’s Messenger (Sallallahu alaihi wasallam) said, “You will not enter Paradise until you believe; and you will not believe until you love one another. Shall I not guide you to a thing which, if you do, you will love one another: spread (the greeting of peace) Salaam amongst yourselves.”

Abu Umamah (radi Allahu anhu) narrated: Allah’s messenger (Sallallahu alaihi wasallam) said,” Indeed the person nearest to Allah the Exalted is the one who is foremost in them in offering Salam.”

Abu Hurrairah (radi Allahu anhu) narrated : Allah’s messenger (Sallallahu alaihi wasallam) said,” The younger person should greet the older one, and the walking person should greet the sitting one, and the smaller number of people should greet the larger number of people.”

Abu Hurairah (radi Allahu anhu) narrated: The Messenger of Allah (Sallallahu alaihi wasallam) said, “A rider should greet a pedestrian, a pedestrian should greet one who is sitting, and a small group should greet a large group (of people).”

Anas bin Malik (radi Allahu anhu) narrated that the Messenger of Allah (Sallallahu alaihi wasallam) passed by some children and greeted them.

Anas (radi Allahu anhu) narrated that the Prophet (Sallallahu alaihi wasallam) used to visit the Ansar and greet their children and patted/touched their heads.

Anas bin Malik (radi Allahu anhu) said: O Messenger of Allah (Sallallahu alaihi wasallam) “Should we bow down for others? He (Sallallahu alaihi wasallam) said No. We said,” Should we embrace one another?” He (Sallallahu alaihi wasallam) said: No, but you should shake hands with one another.

Al Bara (radi Allahu anhu) narrated: Allah’s messenger (Sallallahu alaihi wasallam) said, “Two Muslims will not meet and shake hands without having their sins forgiven before they depart.”